The state cessions are those areas of the United States that the separate states ceded to the federal government in the late 18th and early 19th centuries. The cession of these lands, which for the most part lay between the Appalachian Mountains and the Mississippi River, was key to establishing a harmonious union among the former British colonies. The areas ceded comprise , or 10.4 percent of current United States territory, and make up all or part of 10 states. This does not include the areas later ceded by Texas to the federal government, which make up parts of five more states. Background Most of the British American colonies were established in the 17th and early 18th century when geographical knowledge of North America was incomplete. Many of these colonies were established by royal proclamation or charter that defined their boundaries as stretching "from sea to sea"; others did not have western boundaries established at all. These colonies thus ended up with theoretical extents that overlapped each other and conflicted with the claims and settlements established by other European powers. The British government's Royal Proclamation of 1763, while not resolving the disputes over the colonies' trans-Appalachian claims, succeeded in slowing down the movement of people into the region and the making of new claims in it. Many, however, ignored the proclamation, and various frontier settlement enterprises, owing allegiance to disparate colonial governments, continued. By the time of the American Revolution, the boundaries between the Thirteen Colonies that became the United States had been for the most part surveyed and agreed upon. Their land claims also corresponded in varying degrees to the actual reality on the ground in the west at the eve of the Revolution. Kentucky, for instance, was organized into a county of Virginia in 1776, with Virginia serving as practical sovereign over the area until its admission into the Union as a separate state in 1792. Massachusetts' claims to land in modern-day Michigan and Wisconsin, by contrast, amounted to little more than lines drawn on a map. The Treaty of Paris (1763) that ended the war known as the French and Indian War in North America had France cede most of its claims to land on the continent to Great Britain and Spain. Great Britain, gaining the eastern half of France's southern lands, extended the claims of its colonies of Massachusetts, Connecticut, Virginia, North Carolina, South Carolina, and