The American colonies and the new nation grow rapidly in population and area, as pioneers push the frontier of settlement west.

The process will finally end around 1890–1912 as the last major farmlands and ranch lands are settled.

Native  tribes in some places resist militarily, but they had been overwhelmed by settlers and the army and after 1830 had been relocated to reservations in the west.

The highly influential "Frontier Thesis" of Wisconsin historian Frederick Jackson Turner argues that the frontier shaped the national character, with its boldness, violence, innovation, individualism, and democracy.