"In the years between the Civil War [1861-64] and the Spanish-American War , the health of the army improved drastically. The new concern for soldiers' well-being; the emphasis on sanitation, which became realizable in the new buildings at the larger posts; the new recreation and athletic facilities—all contributed to a healthier and more cheerful environment.
Edward M. Coffman, The Old Army: A Portrait of the American Army in Peacetime, 1784-1898
As the Indian Wars wound down by 1890, the Army closed frontier posts across the West and redeployed troops. The Presidio, with nearby rail and ship transport, was an ideal place to locate soldiers who could be quickly dispatched across the West or the Pacific.
These five large barracks, built in 1895-97, were the first brick buildings at the formerly all-wood Main Post. Each of these U-shaped barracks housed two companies of 109 men each. All five barracks had company offices, large day rooms for relaxation, mess halls and kitchens on their first floor and large open dormitories on their second floor. Latrines and showers were in the basement.
"Rock of the Marne"
The 30th U.S. Infantry Regiment, was highly decorated by the French government for pushing back the German offensive at the Marne River in July 1918.
They occupied these barracks from 1922 to 1941 and were known as "San Francisco's Own".