John L. O'Sullivan

John Louis O'Sullivan was an American columnist, editor, and diplomat who is known for coining the iconic phrase "manifest destiny" in 1845, in order to promote the annexation of Texas and the Oregon Country into the United States. O'Sullivan was an influential political writer and advocate for the Democratic Party at the time, who also served as U.S. minister to Portugal during the administration of President Franklin Pierce (1853–1857) and President James Buchanan (1857-1861).