The third-oldest Army installation in the United States, Fort McNair is nationally-significant for its architecture and military history, as well as its associations with military education, health, and medicine. In addition to its original use for defense of the city, it has also served as a penitentiary, barracks, hospital, and college.
During the Civil War, the arsenal housed 1,000 beds for care of the wounded and also manufactured large quantities of ammunition for the war effort. An 1861 explosion at the Arsenal caused the city’s largest loss of life during the war. In the years that followed, the penitentiary at Fort McNair garnered national recognition as the site of the imprisonment and trial of the conspirators in President Lincoln’s assassination. Mary Surratt and three others were hanged in the prison courtyard on July 7, 1865.
Major Walter Reed, a faculty member at the U.S. Army Medical School from 1893, conducted exhaustive research on malaria at the post hospital and nearby Potomac tidal flats; in 1898 he reported his findings identifying mosquitoes as carriers of the disease. That same year, the post hospital was designated as the Army General Hospital. It was later renamed in Reed’s honor and remained at Fort McNair until 1909, when it moved to its current location on Georgia Avenue.
Following modernization after the Spanish-American War, Fort McNair became the Army's center for the education and training of senior officers with the birth of the Army War College in 1901. The entire installation was redesigned by McKim, Mead & White as a Beaux-Arts campus around the war college building on Greenleaf Point.
In 1924, the Army Industrial College was founded at McNair in order to prepare officers for high level posts in Army supply organizations, and to study industrial mobilization. It evolved into the Industrial College of the Armed Forces. The Army War College was reorganized as the Army-Navy Staff College in 1943, becoming the National War College in 1946 and the National Defense University in 1976.
The post was renamed in 1948 to honor Lt. Gen. Lesley J. McNair, commander of Army ground forces during World War II, who was headquartered at the post and killed in Normandy in 1944. Fort McNair has been the headquarters of the Army’s Military District of Washington since 1966.
The Fort McNair Historic District includes 51 contributing buildings dating from 1791 to 1944.
DC Inventory: November 8, 1964 (Joint Committee on Landmarks)
National Register: December 22, 1978