-Come with us on a journey along what George Washington called the nation's river, the Potomac.

From the lush green of the Shenandoah River valley, past the nation's capital and to the majesty of Chesapeake Bay.

This journey shall take you through the ancient terrains of indigenous people... -We understand Mother Earth to live.

You have veins.

The Potomac is one of the major arteries.

-...slice through roiling waters and along the front lines of the Civil War... -We've had so much evolution here, in the cradle of America, along the Potomac River.

-...glide close by to the splendor of Washington, D.C., and pluck from its waters a most sought-after treat.

-The Potomac River blue crabs are known to be some of the best.

-We will travel this waterway with the people who live, work, and play on it, and through them, get close to the very heart of America.

-There are some beauties that you just can't put a price on.

-This is the story of a waterway once tracked by George Washington.

-It is the soul.

The Potomac River is the main artery of our nation.

-The Potomac, one of the most scenic river journeys in the world.

♪♪ ♪♪ The Potomac has been called the fertile crescent of American history.

From ancient times through the days of English kings to the founding of a new and mighty independent nation, it has all happened along these shores.

♪♪ We begin our journey on the so-called South Branch of the Potomac River at Arnold's Farm, near Moorfield, West Virginia.

♪♪ Known as the Shenandoah Valley, this area has some of the richest farming land in the country, all thanks to the river.

-My family's owned the farm since 1938.

Worked here with my great granddad since 1892.

-John was born and raised here.

-Back in the day, when we were 12, 15 years old, we through square bales of hay, 40-50 pound bales of hay, and stack them in the barn.

It's always hot as can be.

So we'd get done, we'd run to the river and dive in.

♪♪ The river bottom ground has always been very fertile ground because of the floods and bringing in silt and deep topsoil along the river.

There's not a rock in these fields.

It's just deep topsoil, 30 -- 20-30 feet deep.

They say there's some ground up in there that's as deep as Illinois and Iowa, and they grow some big corn up in there.

The fertileness of the ground and being able to stand over here at the river and look across 2000 feet of flat fields and see the mountains in the background, I thought everybody knew it was beautiful.

I mean, look.

♪♪ -John and his buddy, Wayne, are about to do what locals here call floating.

♪♪ -3 or 4 weeks ago, it had gotten really dry in this area, so the river was dropping an inch or two a day.

So then we had the Tropical Storm Ida come through and give us three inches of rain, and even more than that up the country, and raised it up 2 or 3 feet.

And now it's settled back down where it's perfect level to be floating.

I guess I should have let you know I was getting in, huh?

-Yeah.

[ Laughter ] ♪♪ -I was born in D.C., so I've always had a connection to the river.

This water flows through my veins.

It's in my soul.

There's no words to describe it.

It's a special, special place.

And the history here is just -- it started here.

-This is the only river I've really been on.

I've never floated another river.

It's the only one I've ever kayaked.

It's definitely in my blood.

♪♪ -And it's in the blood of the nation, too.

Back in the 1750s, George Washington surveyed much of the lands through which we float.

♪♪ And from here we'll follow in his footsteps downstream to Harpers Ferry, the crucible of the Civil War, before dropping down the Cascades at Great Falls National Park to flow through the nation's capital with those who keep a vigilant watch on the Potomac's health.

From there, we'll pluck from its waters its most delectable treats, paddle through a graveyard of sunken ships at Mallows Bay, see the last surviving lighthouse of its kind at Point Lookout, before frolicking with the bottlenose dolphins of Chesapeake Bay.

♪♪ ♪♪ As they float on down the Potomac, John and Wayne are about to enter a section that George Washington called "the trough."

The name is still recognized today.

-It's a seven-mile stretch where it goes between two mountains, and it's very steep, 800 feet up to the top, because it kind of looks like a hog trough, and the river backs up and that drops silt into the ground and makes that super fertile.

It's pretty uninhabited.

There's eagles nesting there.

♪♪ -The still waters of the trough have just enough flow in them for locals to enjoy the pastime of floating.

No motorized boats here.

Paddles are the most thrust these waters feel.

♪♪ Visitors can rent a canoe at the Trough Outfitters general store.

But if you do float, there is one thing you cannot do.

-You can't get out of there.

Once you get in the trough, you can't walk up over the hill.

You're in the river until it comes out here to the store.

There's no getting out of it.

The river brings us all together in a way.

When you're here, it's not about you.

You're here to enjoy the nature.

You're here to absorb it, to breathe it in, you know?

And this river is life.

If you don't have water, you don't have life.

And that's from the beginning.

-The glistening of the river coming down -- it's pretty awesome place to just sit and let your mind go away, for sure.

♪♪ -The river broadens, and we begin our journey into the very heart of American history.

These waters may seem a calm and peaceful place today, but just over 150 years ago, they formed a border between the two sides in America's Civil War, a vicious fight over the right to keep slaves that led to the deaths of over half a million Americans.

And it's through that history that much of our voyage will flow.

-It is the soul.

The Potomac River is the main artery of our nation.

♪♪ -The steep banks of the trough give way, the horizons lower and reveal the lush expanses of the Shenandoah Valley.

The pace of the meandering flow gently picks up as the river twists and turns for 160 kilometers... ♪♪ ...eventually becoming the state line, with West Virginia on the right, Maryland on the left.

This was the dividing line between the two warring factions in the 1860s, when America tore itself apart over the issue of slavery.

-The Potomac River is the boundary between the United States of America and the Confederacy.

♪♪ -In our journeying from the rich farmlands of West Virginia to the state border with Maryland, we have drifted into the heart of America's Civil War, a five-year bloodbath fought over the issue of slavery.

And at our next stop, the historic town of Harpers Ferry, Dennis Frye has lived his life surrounded by the ghosts of this great conflict.

-Kids like to play war before we understand the horrors of war and the real meaning of war.

But we like to play war.

It's a game.

And when I played with my peers in the fourth grade, we didn't build our forts.

We played in real forts.

-Dennis turned his childhood fascination with Harpers Ferry into a lifelong career.

He is now chief historian at Harpers Ferry National Park.

-We've had so much evolution here -- natural evolution, human evolution, and the evolution of America, in many respects, here, in the cradle of America along the Potomac River.

This is called the point because of the confluence of the two rivers.

♪♪ It also was the point where the ferry operated.

It's also the point where the railroads came together here at Harpers Ferry, historically.

It's also the point where John Brown launched his war against slavery.

-For years, tensions between pro and anti-slavery states had been rising, and in 1859, things came to a head when a leading abolitionist, John Brown, raided the armory at Harpers Ferry to get weapons for what he hoped would be an armed uprising against slavery.

-Brown targets Harpers Ferry for its weapons.

It was a very small number of men -- 18.

Everything is stealth.

Everything's going perfectly until the late night train arrives, and then the whole plan begins to unravel.

-The night train conductor managed to alert the authorities in Baltimore, and ultimately, the US Marines arrived to take control.

-Brown is captured here, and his scheme to end slavery fails.

But many historians believe, and many Americans concur, that John Brown was a bolt of lightning into the heart of American slavery -- the powder keg that blew up and ignited the Civil War that ultimately brought an end to slavery.

-Two years after Brown was captured, 3 million Americans were engaged in a bitter civil war with pro-slavery Confederate states pitched against the anti-slavery forces of the Union.

-The Potomac River is the boundary between the United States of America and the Confederacy, the Confederate States of America, a new fledgling country.

Harpers Ferry is critical to the United States' war effort because of the Baltimore and Ohio Railroad, which is a principal source of supply and communication for the United States.

Hence, the Confederacy also targets this location.

Harpers Ferry would change hands eight times between South and North.

-For five years, the banks of the Potomac would witness bloody battles for the very heart of America, battles which still echo on today.

♪♪ Leaving those turbulent times behind us, we head downriver into a very different kind of turbulence, but one no less life-threatening.

Our next stop is the rapids of Great Falls National Park, about 73 kilometers downstream from Harpers Ferry, formed as the river drops off the high plateau lands below the Appalachian Mountains and down onto the flat Atlantic plains below.

These rapids reach the most extreme grade of volatility, a five-plus rating, and they were once illegal to paddle.

Not that one man cared.

-I'm a bit of a folk hero in these parts.

I've been kayaking the Potomac since I was about 12 years old.

I paddled it.

-Nowadays, Tom is more of a spectator than a paddler, but he is still venerated by those who followed him -- men like Steven McKone.

-The legend of Tom in the Potomac is him and his buddies.

They slept out on a rock here on the river -- because it was illegal to run the falls back in the day -- and so in the early morning, before the sun came up, they paddled up the Mather Gorge to get to Great Falls, and then they ran the first drop.

-A drop is kayaking code speak for actually going over the falls.

-Tom's whole thing was, you know, with the first ascent, you know, it doesn't count unless you do it three times, because the first time could be locked, the second time it could be locked, and the third time means that it's really possible.

And so they ran it three times in a row.

♪♪ They kept it a secret for so long and did it without anybody else knowing.

-But news did get out, and now this part of the Potomac is one of the great whitewater kayaking areas of the whole country.

And as Tom watches on, Steven spends his working days introducing the next generation to the wonders of the Potomac Rapids.

-I run the kayaking school here.

We call it the River School.

My dad was in the Marines, so we kind of moved all over.

And then we moved back to Poolesville, which is just upriver here, when I was 14, and then I've kind of been here since.

♪♪ -And if kayaking these rapids isn't exciting enough... ♪♪ ...someone just downstream tackles them standing up.

♪♪ Not far along from the Great Falls is Guillermo Loria.

He tackles these rapids the same way he once rode the ocean surf in his native Costa Rica.

-I whitewater stand-up paddle.

I paddle the different rapids below Great Falls here on the Potomac River.

♪♪ Well, the challenges that you find paddling the Potomac River are the same as you would find paddling any body of water.

It's a dynamic environment, and it's not so much harnessing it, but is working with it.

Like, understand, oh this current's moving this way.

I'm going to need to angle my board a certain way to make sure I effectively maneuver where I want to go.

There's this mutual understanding of the force that's below you and not working too hard against it, but letting it help you, like a friend would.

♪♪ ♪♪ -Guillermo's love of these waters, with its force and flow, shows how the Potomac can bring serenity and calm, even at its most boisterous.

-I definitely feel a connection to the Potomac River that some would describe a spiritual.

It fills my bucket.

It replenishes me.

♪♪ The Potomac speaks to me.

The friends that I speak to all the time, the friends that I call when I'm having a rough time, they're friends that I've met through paddling.

The Potomac, to me, is almost like a friend.

♪♪ ♪♪ ♪♪ ♪♪ -We have now left the high plateau lands through which the upper river flowed and are on the low, flat Atlantic plain.

♪♪ Here, the river could not be more different -- wide, flat, and slow-moving.

And it's here the Potomac truly becomes the nation's river, as the nation's capital rises on its banks.

♪♪ In 1790, all this was open fields.

But with victory in the War of Independence, the new United States of America needed a capital, and George Washington chose 160 kilometers on the banks of the Potomac to create a city that would ultimately bear his name.

♪♪ Now, the nation's capital is a city of over 5 million citizens, and almost all of their water comes from the Potomac.

♪♪ It's here that the river becomes essential to the very being of those who live on its banks.

-It provides drinking water to 5 million people.

Hundreds and thousands of people recreate on this river every year.

So it's just a vital resource.

It's the lifeblood of this region, and it's the reason we're all here.

-Dean is one of the many people who watch over the health of the waters relied upon by humans and wildlife.

-I've been a riverkeeper now for six years here on the Potomac.

So when you take this job, you take that on, and you stand up, you are basically the voice for the river because the river can't speak for itself.

-Here's the lab analysis.

♪♪ -Dean and his team, including scientist Lisa Wu, work aboard one of the vessels in a fleet that monitor the entire length of the Potomac.

-I'm the lab manager aboard the Sea Dog, and I oversee all of our water quality monitoring volunteers that collect water samples along the Potomac.

♪♪ ♪♪ We wouldn't be able to cover such an area without all of these volunteers.

-And it's vital work, as the health of the capital relies on the Potomac being as clean as it can be.

-These are the samples that have been brought in by our volunteers.

This sample has been incubating for 24 hours, and the yellow indicates their total coliform, which are bacteria that wash into the river and can indicate that there are harmful bacteria that could cause a water-borne illness.

To see if it's a more dangerous strain, we look for fluorescence.

So I'm putting it under our light.

And I'm going to count the fluorescent cells that I see in the sample.

♪♪ -The riverkeepers make sure any pollution is dealt with by alerting authorities and sometimes by legal action.

♪♪ -We patrol the river.

We serve as the voice, the watchdog, investigate pollution, eliminate sources of pollution, use every tool that we have in the tool shed to fix a problem.

Everything we do is based on science and law.

-Thanks to the efforts of these impassioned volunteers and keepers, there is good news.

-I think the river is improving.

Different sites have different issues that have to be dealt with.

This is a historic river, so we're still experiencing overflow from sewers after a big rainstorm, as an example.

But things are improving.

♪♪ ♪♪ -I'm very passionate about clean water.

I think every waterkeeper is, really.

But when you get out and your vacation is spent on rivers, and a lot of what you do in your spare time is on the water, it just kind of is part of your soul.

♪♪ ♪♪ -From the headwaters he surveyed past the Capitol he founded, George Washington and the Potomac River have always been linked.

And 32 kilometers downstream, we come to his final resting place, Mount Vernon, his home until his death in 1799.

From here, we see the Potomac looking much the same as it would have when he gazed upon it and nicknamed it the nation's river.

♪♪ There is a treasure within the Potomac that has been harvested for generations.

♪♪ Soon, we shall meet someone whose ancestors pursued them since the times of George Washington.

-The Potomac River crab can get some of the best and biggest tastes just because of the water here.

♪♪ We have traveled from where George Washington surveyed the headwaters of the Potomac as a young man to where he lived and is now buried, Mount Vernon.

It was he who built the city where today millions of people live.

♪♪ And along its banks, people still make a living in the same way they did back then.

The fishermen, or as they are known locally, the watermen, of the Potomac.

-I love everything about crabbing.

From when I was a little kid, that's, you know -- that's all I've ever been around, and it's all I've ever wanted to do.

♪♪ It's a lot of hard work.

I make all my pots, hand-make everything.

♪♪ -Thanks in part to the work of the riverkeepers, the fishing here is in a good state, with a crab population of around 250 million, more than enough to keep waterman Jimmy Foster in business.

-I'm a seventh generation commercial waterman.

My family has worked on the Potomac for the last five generations, including myself.

I'm like a squirrel trying to find its nuts.

♪♪ The Potomac River is a special place for everybody that works out here.

I mean, it's part of you growing up.

It's all we do.

The river is definitely something that's in our blood.

Well, this is a male, and this is a female.

Um, you can see the bottom of them is a different.

We call this the apron.

Um, the females and the males, as you can see, are different.

Locally, we call this a Jimmy for the male, and the female we call a sook.

And the girls always paint their fingernails, as you can see.

-The season lasts from April to the end of November.

Jimmy and his fellow watermen will catch over 300,000 kilograms of blue crabs each year.

-The Potomac River crab can get some of the best and biggest tastes just because of the water here.

There's a certain salinity, and each crab in this area, you can almost taste a slight difference between, say, a Rappahannock River crab and a Potomac crab.

♪♪ -Magnificent oysters are also harvested here.

And it's over these two riches of the river that a conflict once arose between the two states that sit astride the Potomac.

You see, the state line between Maryland and Virginia does not, in fact, go down the middle of the river.

Thanks to charters issued way back in the days of English kings, Maryland extends its state line right to the shore of Virginia.

No big deal, you might say.

Oh, but oysters and blue crabs.

This has led to a long history of what were known as the Oyster Wars.

The last eruption of them was in the 1950s.

-Maryland owns the Potomac River, and there were watermen on both sides of the river.

So in Virginia we shared the shoreline, and there was watermen over here that worked the oyster beds, just like the Maryland guys.

And the Maryland entities did not want us out there.

So back in the '40s and '50s, the Maryland Marine Police would police the river over here, and these guys on the Virginia side would come out and dredge at night illegally for oysters.

And the Maryland police boats at that time had air-cooled machine guns on the boat, and they would fire on them.

-This was the last of a long history of conflict on the water that stretches back to the Civil War.

The matter was resolved by the Interstate Commission on the Potomac River basin, a governing body formed by the US Congress that dealt with matters of the Potomac's conservation.

Despite efforts to change the boundary to this day, the state line of Maryland is still at Virginia's riverside edge.

♪♪ There are other treasures beneath the water in the Potomac -- perfectly unusual treasures.

We are 65 kilometers downriver from Washington, D.C.. Strap yourself into a kayak to see a most wonderful nautical graveyard.

♪♪ ♪♪ -This is an abandoned fleet, intentionally scuttled, almost 100 World War I-era wooden steamship vessels that are now being reintegrated into nature.

♪♪ -Out on the water, local kayaker Shellie Perrie is encountering one of the youngest ships in the graveyard.

-The Accomack is one of the first ships you notice when you come to Mallows Bay.

It was a freighter back in the '20s.

There are over 80 ships out here in Mallows Bay, from the World War I era that were the cargo ships, and then there are also other ships from different eras.

-The Benzonia is probably the other most visible ship in Mallows Bay.

Hurricane Isabel lifted up the Benzonia and put it on top of another vessel, called the Caribou.

♪♪ It's quite the story.

When World War I was going on, about halfway through the war, the allies asked the U.S. to send ships.

Woodrow Wilson was president at the time, and he set forth a proclamation that the US will build 1,000 ships in 18 months to support the war effort, but the war ended before the thousand ships could be built.

About 300 and some were actually built.

♪♪ -Over time, other ships from World War II and merchant fleets were brought here as well, and people were granted permission to salvage what they could off the abandoned ships.

Eventually, the half-submerged and stripped-down hulls were burned to the waterline and left to nature.

-The ships themselves become flowerpot wrecks.

It's very much like a flower pot.

It fills in with silt and sand and soil.

And then between birds and wind, the seeds get planted.

And then once the seeds get planted, they kind of take off.

-The entirety of the 18 square miles is listed on the National Register of Historic Places, lending incredible significance not just to the ghost fleet, but to the totality of the peoples and the heritage dating back thousands of years.

Now that it's a national marine sanctuary, there's renewed attention on those ships as being a catalyst and a gateway to some of these broader stories of people and heritage and history of the Potomac River.

♪♪ -One of those stories is where the Potomac River finally meets the sea, where stands a lighthouse that lit up the New World... ♪♪ ...and took prisoners.

♪♪ Standing where the Potomac empties into Chesapeake Bay, we see the historic lighthouse at Point Lookout.

-Point Lookout was surrounded by treacherous shoals.

A lot of ships would run aground.

A lot of ships would sink.

It was loosely charted.

So the federal government, around 1825, said, "Well, we need a series of lighthouses that we're going to actually construct throughout the Chesapeake side, with this being the anchor here at Point Lookout."

♪♪ -Bob Crickenberger is chairman of the Friends of Point Lookout.

-I've been a volunteer here for 43 years.

♪♪ An architect named Donahue was awarded the contract for these lighthouses to be constructed, they'd be known as Donahue's Dozen, of which this is one of the last of those to exist from that.

♪♪ -Built to save lives at sea, Point Lookout became more famous for saving lives on land when it became a hospital and then a prison during the Civil War.

-Growing up, I was extremely interested in the Civil War, and talking to a lot of the older family members, some of them were old enough that they remembered speaking to some of our ancestors who fought during the war, and they kept bringing up Point Lookout, Point Lookout.

So I went looking for Point Lookout.

And I showed up here in January, 1978, and I met the park manager then, the ranger, Gerald Sword, and he said, you know, we really don't have a budget to preserve this.

And he said, if it's going to be saved, it's got to be done by volunteer labor, and I've been here ever since.

I showed up one day with a pick and a shovel.

♪♪ My family came from the Shenandoah Valley in Virginia, and they fought for the Confederacy.

♪♪ On May 12th, 1864, two of my ancestors were captured.

And very shortly after that, 2 or 3 days later, they were here at Point Lookout.

♪♪ It was only supposed to hold 10,000.

By April of 1865, there's almost 23,000 prisoners jammed in the prison camp.

-Point Lookout went from lighthouse to being the site of one of the largest military prison camps in the American Civil War.

-They allowed prisoners access at certain hours and during the day to come out and fish, do their laundry.

Just relax on the beach.

They could crab.

If ducks should wander too close to their restricted area, they would duck hunt.

They write about lounging on the beach and watching the vessels go by and listening to the seagulls.

-For historian, nature lover, and patriot like Bob, Point Lookout is a wonder, a spot blessed by Mother Nature and which connects him and us to those who played a life and death role in nation-building.

-I've been asked, why do I love it so much?

Or why do I like being here?

♪♪ I look at the same scenery that the early explorers looked at and the Civil War soldiers looked at, the same areas that they write about, that they write home about, that they write in their journals about it.

It's the best of both worlds.

You know, I can be immersed in nature and I can be immersed in history.

I have the woods, I have the water.

What's not to like?

♪♪ -It's the mouth of the Potomac that can be seen as the very start of an important chapter in American history.

-This is where expansion starts, you know.

After we go through the French and Indian War, the Seven Years War, and then the American Revolution and Western expansion takes off, we reach north and south through the Potomac, but we also reach from east to west.

To me, the Potomac is almost the lifeblood of American history.

-We approach the spectacular end of our journey.

We have coursed through ancient lands and tumultuous history, and have seen how a new nation emerged on the banks of this storied river.

As Point Lookout overlooks the Potomac's final flows, we arrive in our final stop, the spectacular Chesapeake Bay.

This is the largest estuary in the entire United States.

It was formed by a meteorite, which left a broad and shallow crater that would fill with water as the continents shifted.

It has been said that Chesapeake Bay is America's prettiest body of water, and doubtless, it's true.

Shielded from the ocean, the waters are frequently glassy.

Sailing is a passion for many here, the sunsets magnificent.

It's a haven for shoreline birds and a stopover for migratory species.

Below the surface of the bay, it teems with fish, crab, oysters, and, in the warmer times of the year, such as now, the much-adored bottlenose dolphin.

♪♪ -Yeah.

-Yeah, Helen, you tell us.

-Okay.

-Amber, do you need this rope, or is that one still good?

-I think this one's okay.

We'll just use this one.

-Okay.

Let's use that one.

-Dr. Helen Bailey and her team... -Okay, yup.

Over there.

-...work for the Chesapeake Biological Laboratory at the University of Maryland Center for Environmental Science.

-I grew up in the south of England, and my dad was a sailor, and he really instilled in me this interest in the ocean.

I was fortunate at the end of my PhD to get a job with NOAA, the National Oceanic and Atmospheric Administration in California, and then I moved over to the University of Maryland.

I've been very fortunate to study marine mammals over the last 20 years.

Specifically, I have focused most on the bottlenose dolphin.

-Dr. Bailey's research not only found undeniable data that changed the focus of conservation efforts here, but she also managed to enlist all of Chesapeake Bay to help her help them.

-We've been fascinated by the pictures that we've received from the public.

♪♪ -Dr. Helen Bailey is the preeminent researcher of bottlenose dolphins in Chesapeake Bay.

-It's really important to understand that dolphins are regular visitors to the Potomac River and the Chesapeake Bay, because when the agencies were doing environmental impact assessments, dolphins weren't considered.

So we want to make sure that it's clear these are frequent, regular inhabitants of the Chesapeake Bay, and the bottlenose dolphins should be protected wherever necessary.

♪♪ -And then this hydrophone is listening for the animals under the water.

-We're going to be putting out a hydrophone, so then that can be in the water listening for the dolphins for months at a time.

-Let's let it down nice and gently to the water.

There we go.

♪♪ Dolphins use sound as their primary sense.

And I mean, if you phone your mum and you say hello, she immediately knows it's you because she knows your voice.

But dolphins can't do that, probably because of the way sound propagates in the water.

They have to produce that signature whistle or another dolphin won't necessarily recognize them.

-And by recording them, Helen and her team have proven that there are far more dolphins in the bay than many thought.

♪♪ -Now I'm going to open it up.

We're going to take out the memory card here, and we're going to put that into the computer so that we can then look at those sounds.

♪♪ And here now we can play those sounds and we can hear the dolphins whistling.

[ Dolphins whistling ] Oh we have one here.

That's the signature whistle.

We can identify this individual dolphin has been detected in the Potomac River.

-To study them further, Dr. Bailey invented an app where people anywhere can upload info on their dolphin sightings.

This has engaged the entire Chesapeake community in the cause of dolphin conservation.

-We've been fascinated by the pictures that we've received from the members of the public.

We know that they are coming here to feed, which is a good sign that we have healthy fish stocks, as well as the fact they seem to be breeding.

Here we see evidence of mating behavior as well as young calves.

And even a birth was observed.

So this seems to be an important reproductive area and feeding area for the dolphins.

-Right into its final outflows, the Potomac bears something special.

The history and beauty of the Potomac stirs the spirit and gives a most unique understanding of America.

-As a Brit, I think the Potomac River epitomizes so much about what America is, whether that's the identity as a nation as well as their principles of what they value.

And I think there is something so special about the Potomac River.

There are some beauties that you just can't put a price on.

♪♪ -We end our journey paddling the creeks that line the edge of Chesapeake Bay.

Here we are with Francis Gray, a member of the Piscataway First Nation, whose name means "The People Where the Rivers Blend."

-Archaeology has now disclosed that our ancestors have been here well over 11,000 years.

-By the time the Europeans came, the Piscataway were a large nation, cultivating many varieties of maize and beans, as well as trading with other tribes on the river.

♪♪ -We understand that for a body to live, you would have arteries.

You would also have the veins.

We look at the Potomac as being one of the major arteries.

♪♪ Tribal entities were able to travel down to my historical homelands to trade, to bring goods and to take goods back home.

♪♪ The Potomac River got his name from the English.

The Potomac Tribe actually gave resources to the English during a hard winter to starving time.

♪♪ It was named after those who gave them food.

♪♪ The river was the central point.

The river connected everybody in one way or another.

The life that this river runs through, this body, my ancestors, those that are here today, the descendants -- we're talking about life, what it represents, these different communities.

It's like a body.

♪♪ -And what a body it is.

From the springs and tributaries of the Alleghany Mountains down into the Shenandoah Valley, through Civil War country, along the banks of the national capital, over treasures that lie beneath, and past majestic points that stand as beacons to history and country, we've met descendants, newcomers, and lifelong residents who make the nation's river their home.

This artery supported the indigenous for centuries and helped birth and sustain a new and mighty nation within its waters, along its storied banks, through its passionate people, and deep within its historic places.

We gained an intimate look at the very heart of America.

Unlike any other river in this country, it is the Potomac that flowed through the front lines as America formed, unfolded, convulsed, and prospered.

And in the end, it glistens as the nation's river.

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