Oliver Otis Howard graduated from West Point in 1854 and began his professional career as an army officer and mathematics instructor. During the Civil War he commanded Union volunteers, losing his right arm at Seven Pines in 1862. He returned to duty and rose to corps command. His Eleventh Corps suffered defeat when Stonewall Jackson struck its flank at Chancellorsville in 1863, damaging his reputation and intensifying prejudice against its German-born soldiers.

At Gettysburg, Howard's troops were again driven back on the first day, but he helped establish the Union position on Cemetery Hill, which became essential to the army's defensive line. Transferred west, he served at Chattanooga and in the Atlanta campaign. He then commanded the Army of the Tennessee during Sherman's March to the Sea and the campaign through the Carolinas, gaining experience in large-scale operations.

Appointed commissioner of the Freedmen's Bureau in 1865, Howard supervised efforts to assist formerly enslaved people and war refugees through education, legal protection, relief and labour arrangements. The bureau confronted white resistance, limited resources and conflicts over the restoration of land to former Confederates. His paternalism and support for contract labour drew criticism. He helped establish Howard University in 1867 and served as its president, linking his religious commitments with the promotion of education for African Americans.

His western military service exposed a sharp contradiction in his record of humanitarian reform. As commander in the Pacific Northwest, he enforced demands that non-treaty Nez Perce move to a reservation and pursued them during the war of 1877. Subsequent commands included operations against other Indigenous peoples and leadership of West Point. Retiring from the army in 1894, he wrote and remained active in religious and educational causes. His career combined advocacy for Black citizenship with coercive expansion over Indigenous communities.