Alexander McDowell McCook

Alexander McDowell McCook (April 22, 1831June 12, 1903) was a career United States Army officer and a Union general in the American Civil War.
Early life.
McCook was born in Columbiana County, Ohio. His family was prominent in army service — his father Daniel McCook and seven of Alexander's brothers, plus five of his first cousins, fought in the war. They were known as "The Fighting McCooks", for whom McCook Field in Dayton, Ohio, was named. His brothers Daniel McCook, Jr., Edwin Stanton McCook, and Robert Latimer McCook were all Union generals, as were his cousins Anson G. McCook and Edward M. McCook.
McCook graduated from the United States Military Academy in 1852, served against the Apaches and Utes in New Mexico in 1853–57, and was assistant instructor of infantry tactics at the military academy in 1858–61.
Civil War.
At the start of the Civil War, McCook was appointed colonel of the 1st Ohio Infantry in April 1861. He served in the Washington defenses and saw action at the First Battle of Bull Run. On September 3, 1861, he was promoted to brigadier general of volunteers and commanded a division in Tennessee. He earned the brevet of lieutenant colonel in the regular army for his part in the capture of Nashville, Tennessee. McCook then commanded the 2nd Division in the Army of the Ohio at the Battle of Shiloh on the second day of fighting, and then in the subsequent campaign against Corinth. He was promoted to major general of volunteers on July 17, 1862.
McCook was given command of the I Corps in the Army of the Ohio. His corps suffered heavy casualties and driven back a mile at the Battle of Perryville in October 1862. Command of the Army of the Ohio was reorganized and his command designated the Right Wing of the XIV Corps in the new Army of the Cumberland. His command again suffered heavy losses at the Battle of Stones River. Once again the command structure was reorganized and his corps named the XX Corps. For the third and final time, at Chickamauga, McCook's troops suffered heavily and were driven from the field. He was courtmartialed and partially blamed for the Union disaster at Chickamauga. He was not convicted but relieved of duty in the Army of the Cumberland.
He waited almost a year before receiving another command assignment of any kind. It came thanks in part to Confederate General Jubal Early and his threat against Washington, D.C. McCook was placed in command of the "Defenses of the Potomac River and Washington" and was in charge of all forces defending the capital at the Battle of Fort Stevens. The day the battle ended, so did McCook's command of the city's defenses and he was again without command. At the close of the war he was given command of the District of Eastern Arkansas. He received brevet promotions to brigadier general and major general in the regular army for service throughout the war.
Postbellum career.
McCook resigned from the volunteer service in October 1865 and was commissioned lieutenant colonel of the 26th Infantry in March 1867. He served in Texas, mostly in garrison duty, until 1874. From 1875 to 1880, he served as the aide-de-camp to the general-in-chief of the U.S. Army, Gen. William T. Sherman. From 1886 to 1890 (except for brief terms of absence), he commanded Fort Leavenworth, Kansas, and the infantry and cavalry school there. He then commanded the Department of Arizona from 1890 to 1893 and the Department of Colorado from 1893 to 1895.
McCook became a full brigadier general in 1890, a major general in 1894, and retired in 1895. In 1898–99, he served on a commission to investigate the United States Department of War as administered during the Spanish–American War.
Alexander McDowell McCook died in Dayton, Ohio, and is buried in Spring Grove Cemetery, Cincinnati, Ohio.
The town of McCook, Nebraska, was named in his honor.