Cassius Marcellus Clay, nicknamed "The Lion of White Hall" (October 19, 1810 – July 22, 1903) was an emancipationist from Madison County, Kentucky, United States, and a second cousin of famous politician Henry Clay.
Cassius Clay was a paradox in history, as a wealthy Southerner from Kentucky who became a prominent anti-slavery crusader in the 1830s and 1840s. Ironically, he was the son of Green Clay, one of the wealthiest landowners and slaveholders in Kentucky. He worked toward emancipation, both as a Kentucky state representative and as an early member of the Republican Party.
Clay attended Transylvania University and then graduated from Yale College in 1832. While at Yale, Clay heard abolitionist William Lloyd Garrison speak, and Garrison's lecture inspired Clay to join the antislavery movement. Garrison’s arguments were to him “as water is to a thirsty wayfarer” (Brennan 20). Yet he was also politically pragmatic, supporting gradual legal change rather than the immediatism of the Garrisonians.
In the late-1830s and early-1840s, Clay served three terms in the Kentucky General Assembly, but he lost support among Kentucky voters as his platform became more focused on ending slavery. In 1845, he began publishing an anti-slavery newspaper called the True American in Lexington, Kentucky. Within a month he received death threats, had to arm himself, and barricade the doors of his newspaper office for protection. Shortly thereafter, a mob of about sixty men, members of the local opposition, broke into his office and seized his printing equipment, which they shipped to Cincinnati, Ohio. Clay continued publication there.
Although he opposed the annexation of Texas, he served in the Mexican-American War, much to the dismay of his abolitionist friends. Yet, his connections to the northern antislavery movement remained strong, and Clay was among the founders of the Republican party and a friend of Abraham Lincoln, whom he also supported for the presidency.
Instead, from 1861 to 1862 he was Minister to Russia, where he witnessed the Czar's emancipation edict. After being recalled to the United States to accept a commission as Union major general from Lincoln, he publicly refused to accept the commission unless Lincoln would sign an emancipation proclamation. Lincoln sent Clay to Kentucky to assess the mood for emancipation there and in other border states. Although it is unclear how significant Clay was in Lincoln's decision, following Clay's return Lincoln issued the proclamation.
Clay subsequently returned to Russia from 1863 to 1869, again as Minister, where he was influential in the negotiations to purchase Alaska. Upon his return he founded the Cuban Charitable Aid Society to help aid the Cuban independence movement of Jose Marti. He also began speaking out against robber barons and in favor of nationalizing the railroads. He left the Republican Party, in part, due to President Grant's military interference in Haiti.
Clay died July 22, 1903. Survivors included his daughters, the women's rights activists Laura Clay and Mary Barr Clay. His family home, White Hall, is now maintained by the Commonwealth of Kentucky as White Hall State Historic Shrine.