See biography by J. T. King (1963).
During the Civil War, he saw much service in the Southwest and led an assault at Port Gibson in the Vicksburg campaign in 1863. Carr was awarded a Medal of Honor for his actions at Battle of Pea Ridge in Arkansas, on March 7, 1862. According to the official citation, Carr had "directed the deployment of his command and held his ground, under a brisk fire of shot and shell in which he was several times wounded. Carr rose in rank throughout the war and, by its end in 1865, he was brevetted major general of volunteers.
Subsequently, he conducted successful operations on the frontier against the Indians, winning a significant battle at Summit Springs and became colonel in the regular service in 1879, and brigadier general in 1892, a rank which he held at the time of his retirement in 1893. His military nickname was "The Black-Bearded Cossack
He is buried in the West Point Cemetery, New York.