Almost every American knows the traditional story of July Fourth—the soaring idealism of the Declaration of Independence, the Continental Congress's grim pledge to defy the world's most powerful nation with their lives, their fortunes and their sacred honor. But what else about revolutionary America might help us feel closer to those founders in their tricornered hats, fancy waistcoats and tight knee-breeches?

Those Americans, it turns out, had the highest per capita income in the civilized world of their time. They also paid the lowest taxes—and they were determined to keep it that way.

By 1776, the 13 American colonies had been in existence for over 150 years—more than enough time for the talented and ambitious to acquire money and land. At the top of the South's earners were large planters such as George Washington. In the North their incomes were more than matched by merchants such as John Hancock and Robert Morris. Next came lawyers such as John Adams, followed by tavern keepers, who often cleared 1,000 pounds a year, or about $100,000 in modern money. Doctors were paid comparatively little. Ditto for dentists, who were almost nonexistent.

In the northern colonies, according to historical research, the top 10% of the population owned about 45% of the wealth. In some parts of the South, 10% owned 75% of the wealth. But unlike most other countries, America in 1776 had a thriving middle class. Well-to-do farmers shipped tons of corn and wheat and rice to the West Indies and Europe, using the profits to send their children to private schools and buy their wives expensive gowns and carriages. Artisans—tailors, carpenters and other skilled workmen—also prospered, as did shop owners who dealt in a variety of goods. Benjamin Franklin credited his shrewd wife, Deborah, with laying the foundation of their wealth with her tradeswoman's skills.

Several hundred miles inland was the "back country," and at the time of the Revolution, not many people went there by choice. Most were poor and landless—younger sons, for example, whose older brothers had inherited the family's property. Life on the outskirts of civilization was hard and often violent. Morals on the Western frontier were often much more relaxed than they were in the civilized East.