John L. O'Sullivan coins 'manifest destiny' in the United States Magazine and Democratic Review

Background. John Louis O'Sullivan was an American columnist, editor, and diplomat known for coining the phrase 'manifest destiny' in 1845. He founded and edited The United States Magazine and Democratic Review in 1837, which was based in Washington. O'Sullivan was an influential political writer and advocate for the Democratic Party, using his platform to promote the annexation of Texas and the Oregon Country into the United States.

Coinage of the Phrase. The phrase 'manifest destiny' first appeared in O'Sullivan's July–August 1845 editorial titled 'Annexation' in The United States Magazine and Democratic Review. Historians credit O'Sullivan with coining the term in 1845. The concept was used by Democrats to justify the 1845 annexation of Texas and the 1846 Oregon boundary dispute, reflecting the belief that American settlers were destined to expand westward.

Influence and Context. Manifest destiny became a major campaign issue during the 1844 presidential election. O'Sullivan addressed the ongoing boundary dispute with Britain on December 27, 1845, in his newspaper the New York Morning News. The concept influenced American imperialism, with O'Sullivan predicting California and Canada would follow the pattern of annexation, though he was critical of the Mexican–American War in 1846.