From 1776 through 1789, the history of the United States included the formation of the independent country of the United States and the drawing and ratification of its new government. In an attempt to gain autonomy and freedom from the Kingdom of Great Britain, the Americans started a revolution, which grew into a war. The Americans eventually won the war and took control of the land now known as the eastern United States.

This article covers the history of the United States from 1918 through 1945, Post World War I, the Great Depression and World War II.

The history of the United States (1865–1918) covers Reconstruction and the rise of industrialization in the United States.

The American continent ranges from the Pacific to the Atlantic Ocean and includes outlying areas as well. The first inhabitants of the area now claimed by the United States arrived at least 12,000 years ago, probably by crossing the Bering land bridge into Alaska. Relatively little is known of these early settlers compared to the Europeans who colonized the area after the first voyage of Christopher Columbus in 1492.