State cessions

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 236,825,600 acres (958,399 km²), 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.

Most of the British colonies on the east coast of North America 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.

By the time of the American Revolution, the boundaries between the various colonies had been for the most part surveyed and agreed upon in the eastern part of the country, where European settlement was densest. (The one notable exception to this trend was the ongoing dispute between New York, New Hampshire, and independent Vermonters over the land that in 1777 became the independent state of Vermont and in 1791 was recognized and admitted to the Union.) The British government's Royal Proclamation of 1763, while not resolving the disputes over the colonies' trans-Appalachian claims, sought to cool them by placing significant restrictions on European settlement in the region. The proclamation was largely ignored on the ground, however, and various frontier settlement enterprises, owing allegiance to conflicting colonial governments, continued.

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