Between the Wars: 1920-1941

After General Hospital No. 25 discontinued operations, Fort Harrison resumed its former status as a garrison for one regiment of infantry. Various elements of the 20th and 40th Infantry Regiments resided at the post from the close of the war to June 1921. However, a post-war reorganization of the Army that promised to redefine the mission of several established military stations bred a high degree of uncertainty among local citizens about the future of the post.

The resulting National Defense Act of 1920 supplanted the six territorial departments of the 1898 organization with nine corps areas. Each corps area contained one Regular Army division, two National Guard divisions, and a nucleus of three organized Reserve divisions. The legislation named Fort Harrison the new headquarters of the Fifth Corps Area composed of the states of Indiana, Ohio, Kentucky and West Virginia. From August 1920 to June 1922, Brigadier General George W. Read commanded the Fifth Corps and Fort Harrison from the headquarters building bordering the parade ground. In 1922 the War Department announced the relocation of the Fifth Corps headquarters to Fort Hays, Ohio. During the previous year, the 11th Infantry Regiment had begun to garrison the post. Lead elements of the regiment arrived at Fort Harrison in the fall of 1921, beginning a relationship with the post that would last until the nation began mobilizing for another world war in 1941.