Alexander McDowell McCook was born in Columbiana County, Ohio, on April 22, 1831. He was the fifth son of Daniel McCook and Martha Latimer (McCook). McCook received an appointment to the United States Military Academy and graduated on July 1, 1852, thirtieth in his class.
U.S. Army Officer
Upon his graduation from West Point, McCook received a brevet commission as a second lieutenant on July 1, 1852. The army stationed McCook first at the Newport Barracks in Kentucky and then at the Jefferson Barracks in Missouri. In 1853, officials sent McCook west where he scouted and fought against the Apache and the Ute Indians until 1857. On June 30, 1854, while serving in the West, officials promoted McCook to second lieutenant. In 1857, McCook took a leave of absence, and upon his return on February 12, 1858, he served as an assistant instructor of infantry tactics at the United States Military Academy until April 24, 1861.
When the American Civil War began, officials appointed McCook as colonel of the 1st Regiment Ohio Volunteer Infantry on April 16, 1861. After recruiting volunteers and helping organize the unit at Dayton, McCook took part in the First Battle of Bull Run (July 21, 1861). Later that year, on September 3, the War Department promoted McCook to brigadier general of volunteers.
In 1862, McCook received a brevet promotion to the rank of lieutenant colonel in the regular army for his participation in the capture of Nashville, Tennessee in February. During the spring, officials placed him in command of the 2nd Division of the Army of the Ohio, and he took part in the Battle of Shiloh (April 6-7, 1862) and the Siege of Corinth (April 29, 1862-May 30, 1862).
Battle of Perryville
On July 17, 1862, McCook the War Department promoted to McCook to major general of volunteers and assigned him to command of the 1st Corps of the Army of the Ohio. Serving in that role, he suffered the first of several major setbacks in his career when his troops did not perform well at the Battle of Perryville (October 8, 1862).
Battle of Stones River
In December 1862, the War Department reorganized the Union armies in the Western Theater and placed McCook in command of the Right Wing of the 14th Corps in the newly created Army of the Cumberland. Shortly thereafter, McCook’s command performed badly once again at the Battle of Stones River (December 31, 1862-January 2, 1863). After that battle, officials reorganized the Army of the Cumberland and gave McCook command of the 20th Corps.
Battle of Chickamauga
During the summer of 1863, McCook’s Corps took part in Major General William Rosecrans’s Chickamauga Campaign, helping drive Confederate General Braxton Bragg’s Army of Tennessee out of Tennessee. At the Battle of Chickamauga (September 19-20, 1863), however, McCook performed poorly once again, and Confederates drove his troops from the field, inflicting heavy losses. Officials partially blamed McCook for the Union disaster at Chickamauga. Nevertheless, a court-martial exonerated him for his actions on the field. Still, officials relieved McCook of his command when they merged the 20th and the 21st Corps to form 4th Corps commanded by Major General Gordon Granger.
Battle of Fort Stevens
McCook spent the next ten months awaiting orders and a new command. During the summer of 1864, Confederate General Jubal Early launched an offensive in the Shenandoah Valley and threatened Washington, DC. Union officials placed McCook in command of the defenses around the nation’s capital. McCook rose to the occasion and defeated Early’s force at the Battle of Fort Stevens (July 11-July 12, 1864), driving the Rebels back into Virginia. Despite his redemption at Washington, McCook did not have a field command at the end of the Civil War.
Regular Army Duty
After the war, McCook received brevet promotions to brigadier general and major general in the regular army. Officials placed him in command of the District of Eastern Arkansas. McCook mustered out of volunteer service on October 21, 1865, but he remained in the regular army.
On March 5, 1867, the army commissioned McCook as lieutenant colonel of the 26th Infantry and deployed him to Texas, where he served until 1874. From 1875 to 1880, McCook served as the aide-de-camp to the general-in-chief of the U.S. Army, William T. Sherman. On December 15, 1880, officials promoted McCook to colonel of the 6th Infantry. On May 13, 1886, the army appointed McCook as commander of Fort Leavenworth, Kansas, and the infantry and cavalry school. He served in that capacity until August 28, 1890. On July 11 of that year, the army promoted McCook brigadier general. After his stint at Fort Leavenworth, McCook commanded the Department of Arizona from 1890 to 1895. While there the army promoted him major general in 1894.
McCook retired from the army in 1895 and lived his remaining years in Ohio. He died in Dayton on June 12, 1903, at seventy-two years of age. McCook is buried in Spring Grove Cemetery, Cincinnati, Ohio.
McCook was a member of the “Fighting McCooks,” fifteen family members who served the Union during the Civil War. McCook’s father, Daniel McCook and his eight sons who served in the war were known as the “Tribe of Dan.” McCook’s uncle, John McCook and five of his sons who served in the war were known as the “Tribe of John.” Daniel McCook, along with four of his sons (Latimer, Daniel Jr., Robert, and Charles) died from wounds received during the Civil War. Alexander McCook achieved the highest military ranking among the members of the family.