April 18: At 10pm on a Tuesday night, Dr. Joseph Warren sends Paul Revere and William Dawes, Jr. to Lexington to warn Samuel Adams and John Hancock that the British are planning to march there to seize military supplies.
At 11, friends row Revere across the Charles River to Charlestown where a fast horse awaits. Meanwhile, Dawes takes the longer land route through Roxbury.
At 11:30, avoiding two British soldiers, Revere takes the Medford road, awakening all the people in houses along his path.
April 19: The day that history will know as Patriots Day begins.
Dawes catches up to Revere at the Hancock-Clarke House in Lexington. Dr. Samuel Prescott joins the two riders on the road to Concord. The pealing of a bell on the green summons Captain John Parker and the local militia.
Two British soldiers surprise Revere, the lead rider. Dawes cuts back toward Lexington and escapes. Prescott jumps his horse over a wall, rides down by a swamp and continues onto Concord. Revere tries to lose his assailants in the woods, but is captured by another half-dozen British soldiers.
Prescott reaches the Hartwell Tavern and Mary Hartwell carries his warning to the nearby Lincoln minute men.
The Town House bell announces Prescott's arrival in Concord. Meanwhile, the last of the British regulars have finally been ferried across the Charles River from Boston. They begin their march toward Concord.
British General Thomas Gage orders General Earl Percy to lead a thousand-man brigade of reinforcements to Concord; missed messages will delay this group for five hours. In Concord, more of the supply depot is moved out of town, hidden or buried.
An American scout reports that the British are half a mile from Lexington. On Lexington Green, Captain Parker and 77 of his minute men stand in wait.
The British and the rebels face each other across the Green. Parker orders a retreat, but a shot rings out, leading to a full volley from the British. Both sides are engaged as the Colonists flee. Eight Americans are killed and ten wounded.
The British arrive at Concord and begin searching the town for weapons. The minute men watch from positions above the town, aware they are currently outnumbered but gaining troops each moment.
Percy's British relief force finally sets off, taking the land route.