Buell, Don Carlos (1818–1898), a United States army officer. He was born near Marietta, Ohio, and graduated from West Point in 1841. Buell served in the Seminole and Mexican wars. When the Civil War broke out, he was appointed brigadier general of volunteers. His Army of the Ohio helped save General Grant at Shiloh (1862). Buell was promoted to major general the same year. He miscalculated in a campaign in Kentucky and almost allowed the Confederates to take Louisville.
Buell's forces met those of General Braxton Bragg at Perryville, Kentucky, on October 8; after an indecisive battle, Bragg withdrew. Buell permitted Bragg's army to escape and was removed from command. In 1864, following an inconclusive investigation, he resigned his commission and left the service.