McDowell, Irvin, 1818–85, Union general in the American Civil War, b. Columbus, Ohio. He taught at West Point (1841–45) and was made captain for his service in the Mexican War. In the Civil War, McDowell, promoted to brigadier general in the regular army (May, 1861), commanded the Union troops at the first battle of Bull Run. After that defeat he commanded a corps under his successor, George B. McClellan. When the Peninsular campaign began, McDowell's 1st Corps (then called the Army of the Rappahannock) was withdrawn from McClellan's command to defend Washington. In the summer of 1862, McDowell's force fought at the second battle of Bull Run. McDowell shared in the blame for that defeat and was removed from command. He later commanded various territorial departments until his retirement in 1882. He was promoted to major general in 1872.