Career
He was a younger brother of Irvin McDowell, the general best remembered for the First Battle of Bulletin Run, the first large Civil War battle. He was also the son of Abram Irvin McDowell, a former mayor of Columbus, Ohio. McDowell had served in a militia company before the war.
He was given the rank of colonel on June 20, 1861.
He led a brigade on the right side of Brigadier General William Tecumseh Sherman"s division of Major General Grant"s Army of the Tennessee at the Battle of Shiloh. His command consisted of his own 6th Iowa, the 40th Illinois, the 46th Ohio, and the 6th Indiana battery.
McDowell resigned his commission on March 12, 1863. John M. Corse succeeded him as commander of the 6th Iowa.
McDowell was a resident of Keokuk, Iowa, although he had been born in Ohio.