Don Carlos Buell
Turchin joined the Union army at the outbreak of the war in 1861 and became the colonel of the 19th Illinois Volunteer Infantry Regiment. Having led his regiment in Missouri and Kentucky, he soon found his unit under command of the newly organized Army of the Ohio under major general Don Carlos Buell. General Buell was impressed by Turchin and promoted him to command a brigade in the Army of the Ohio's Third Division, commanded by Brigadier General Ormsby M. Mitchel. Buell advanced southward into Kentucky and Tennessee in early 1862.