During the American Civil War, he served as an officer in the Union Army, rising to the rank of brigadier general.

He entered the military service in 1860, as a first lieutenant in the Missouri Volunteer Militia's Southwest Battalion, and served for six months on the frontier of the state.

In June 1861, after the outbreak of the Civil War and the Camp Jackson Affair, he enlisted in the United States Army, and was commissioned a major in the 7th Missouri Volunteer Infantry, known as the "Irish Seventh".

He was with William Tecumseh Sherman in his march to the sea; fought at Resaca, Dallas, Kennesaw Mountain, Jonesborough, and Lovejoy's Station, and in the capture of Savannah and Fort McAllister.

He was a town supervisor in 1878, and ran for the Assembly that year, losing with 746 votes to 989 for Republican Atley Peterson, and 710 for Greenbacker S. L.