Founded in 1776 by thirteen coastal colonies that declared their independence from Great Britain, the United States began its westward expansion following the end of the American Revolutionary War and the recognition of U.S. sovereignty in the 1783 Treaty of Paris. The treaty bequeathed to the nascent republic all land between the Appalachian Mountains and the Mississippi River, and Americans began migrating there in large numbers at the end of the 18th Century, resulting in the displacement of Native American cultures, often through native peoples' forcible deportation and violent wars of eviction. These efforts at expansion were greatly strengthened by the 1787 Constitutional Convention, which resulted in the ratification of the United States Constitution and transformed the U.S. from a loose confederation of semi-autonomous states into a federal entity with a strong national core.