When the American Revolution (1775–83; a war fought between Great Britain and the American colonies in which the colonies won their independence) ended in 1783, Great Britain ceded (formally gave) to the new United States all the territory between the Atlantic Ocean and the Mississippi River except New Orleans and Spanish Florida. In theory, the new country stretched for more than a thousand miles in every direction. However, with the exception of outposts along navigable inland rivers, most Americans lived along a tiny ribbon of settlement along the Atlantic seaboard. In fact, at the time of the revolution, about 95 percent of the total U.S. population resided east of the Appalachian Mountains. Tens of thousands of Indians occupied their ancestral lands within U.S. territory. Many Native American tribes were friendly to newcomers—trading with them and guiding them to new lands. Other tribes, however...