manifest destiny

In US history, the belief that Americans had a providential mission to extend both their territory and their democratic processes westwards across the continent. The phrase ‘manifest destiny’ was first used by the New York Post editor and journalist John L O'Sullivan in 1845. The philosophy was especially expounded by the Democratic followers of President Andrew Jackson, and was one of the main reasons for the USA's westward expansion, initially to California and Oregon, that would last to the end of the 19th century.

O'Sullivan wrote that it was, ‘Our (America's) manifest destiny to overspread the continent allotted by Providence (God) for the free development of our yearly multiplying millions.’ Belief in manifest destiny partly explains the powerful drive, sense of mission, and overwhelming desire and greed to own land (then equated with power) shown by Americans of this era, despite the threats of poor soil, harsh elements, and hostile American Indians.

Reflecting this philosophy, Texas was annexed in 1845, California was ceded to the USA following the Mexican War (1846–48), and Oregon Territory was formally recognized in 1848. In the 1860s, the US government looked to the Great Plains for more land to control, the last large area available for settlement. They displaced the Plains Indians to make way for American homesteaders, confining the Indians to Indian reservations and destroying their way of life. The US government's support encouraged Americans to believe that it was God's will to go west, making their actions seem justifiable.