Beginning in 1940, as military drafting swelled the army and navy with hundreds of thousands of new servicemen, the United States rapidly built reception centers and temporary housing on strategically located military posts, including Jefferson Barracks. During the early 1940s, 275 frame buildings were constructed there, more than 150 of them 63-man temporary barracks built quickly and cheaply under the Army's Quartermaster General and Army Corps of Engineers, with designs emphasizing speed, simplicity, flexibility, conservation of material, and safety. These wooden barracks were not shoddily built: a standard 63-man barracks was 29'-6" wide, 80' long, and two stories tall, rested on concrete footings, housed 63 enlisted men in single bunks or more than 80 in double bunks, contained 4,730 square feet, and cost about $10,000.00 in 1941, with features such as wood framing, sash windows, and continuous eaves that improved ventilation and protected the buildings from weathering. Jefferson Barracks itself was established in 1826 after Fort Bellefontaine was judged unhealthy and unsatisfactory, when Carondelet offered common fields for a new post, and on October 23, 1826, the War Department named it in honor of Thomas Jefferson, who had died six days earlier. Its site near St. Louis on the Mississippi River made it an important permanent post and gathering point for troops and supplies in the Mexican War, Civil War, Indian conflicts, Spanish-American War, Philippine War, World War I, and World War II. In World War II it became a major reception center for draftees, also served as a basic training site for the Army, and later became the first Army Air Corps training site; the post reached 1,702 acres before being deactivated in 1946. From 1950 onward, the federal government conveyed tracts to St. Louis County for a historical park, and in 1971 Jefferson Barracks County Park, the adjacent active military base, and adjoining parcels were placed on the National Register of Historic Places. Active railroad tracks in the park once led to a station at the south end, where thousands of servicemen arrived and departed; the line was originally built by the St. Louis, Iron Mountain, and Southern Railway Company, the depot was constructed in 1902 and operated until 1970, and Missouri Pacific demolished it in 1987.