Antebellum Period

The Antebellum Period in American history is generally considered to be the period before the Civil War and after the War of 1812, although some historians expand it to all the years from the adoption of the Constitution in 1789 to the beginning of the Civil War.

Journalist John O’Sullivan coined the term “Manifest Destiny” in 1845, embracing the belief that Americans and the institutions of the U.S. are morally superior and therefore Americans are morally obligated to spread those institutions. The concept already existed and had to some degree ever since the 13 colonies won their freedom from Great Britain; O’Sullivan gave it a name.

Belief in these principles led many well-meaning whites to try to replace the traditional cultures of nomadic native American tribes with a lifestyle more in keeping with Euro-American farming communities. In other instances, it simply was used to justify the ever-increasing demand for more land in the west.

In 1844, James K. Polk of Tennessee was elected president on a platform of westward expansion. He faced off with the British over control of the Oregon Territory and oversaw a successful war with Mexico, 1846–1848. The Mexican War and settling the Oregon question meant that the United States now stretched from the Atlantic to the Pacific. Western expansion soon took a major leap forward with the California Gold Rush, as thousands from the eastern states, as well as from foreign nations, headed for the territories of California and Nevada, hoping to strike it rich.