The Declaration of Independence contains these words: "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the Pursuit of Happiness."

But what is happiness? And how do you pursue it? There were lots of answers to that question. Some said happiness was being rich. Some said it was going to school, or having a fine family. Some said it could be found in religion, or in being free. Many said happiness was having land. And as the original thirteen states grew more crowded, those who sought land looked west across the Appalachians.

On the frontier no one cared if you were Puritan or Anglican. It didn't matter if your father was a lord or a pauper. Could you be depended upon? Did you tell the truth? Could you shoot straight? Were you brave? That's what mattered on the frontier. And the frontier offered something equally important: land. Land meant everything in a society that lived by farming. Owning land made you feel really free. And since in most parts of the country only people who owned land could vote, you really were more free.

One of those who went was Daniel Boone, the grandson of an independent-minded Quaker and weaver who moved his whole family to the New World in 1717. In 1755, while fighting for the British in the French and Indian War, Daniel Boone heard stories of a land across the mountains that the Indians called kentake—which meant "meadowland." It was said to be a beautiful land, filled with high grasses, birds, buffalo, deer, and beaver. Boone went searching for a way to get over the mountains, and finally found an Indian trail that led through a gap into the rich grasslands of Kentucky. It became known as the Wilderness Road , and it went for 300 miles. By 1790, almost 200,000 people had gone west along the Wilderness Road. Some kept going further and further west, all the way to the Rocky Mountains . A German-born fur trader described the mountain men who went there to explore and trap beaver for the fur market: "In small parties they roam through … the mountain passes. No rock is too steep for them; no stream too swift…. Danger seems to exercise a magic attraction over most of them."