William Lowndes Yancey (August 10, 1814 - July 27, 1863) was a journalist, politician, orator, diplomat and an American leader of the Southern secession movement. A member of the group known as the Fire-Eaters, Yancey was one of the most effective agitators for secession and rhetorical defenders of slavery. An early critic of John C. Calhoun and nullification, by the late 1830s Yancey began to identify with Calhoun and the struggle against the forces of the anti-slavery movement. In 1849 Yancey was a firm supporter of Calhoun's "Southern Address" and an adamant opponent of the Compromise of 1850.