The belief beginning in the nineteenth-century that America was destined to explore and acquire land from the Atlantic to the Pacific oceans was known as manifest destiny. This territorial expansion changed the landscape of North America and opened the country to settlers who were looking to forge a better life for themselves and their families.

Frederick Jackson Turner delivered a paper at the Chicago World's Fair in 1893, on "The Significance of the Frontier in American History," which has become a seminal work in recognizing the significance of the frontier in American history.