Scottish-born John McArthur rose from colonel of the 12th Illinois Infantry to brigadier general in the Army of the Tennessee. He fought at Fort Donelson, was wounded leading his brigade during a Confederate breakout attempt at Shiloh, and went on to serve at Corinth, Vicksburg, Nashville, and Fort Blakeley. He survived the war and had a prominent postwar career in Chicago, serving as public works commissioner during the Great Chicago Fire and later as postmaster.