The Fourth U.S. Army was organized as Fourth Army in the Organized Reserves in 1922 in New York City and allotted to the Regular Army as an inactive unit. It was activated October 1, 1933 and headquartered at the Presidio of San Francisco. The Fourth U.S. Army moved headquarters to Fort Sam Houston January 7, 1944. In July 1971, the Fourth Army was consolidated with the Fifth U.S. Army before being relocated to Fort Sheridan, Illinois in the 1980s. The Fourth U.S. Army was decommissioned in 1991. An active remnant of the U.S. 4th Army is the FAB Reunion Band.


 CWO Claude Hedspeth was the director of the 5th Army Band that replaced the 4th in 1971. In 1993 CWO Donald Barton, Bandleader of the 5th Army Band at Fort Sam Houston, was relieved that the threatened elimination of the band had been thwarted by pressure from Fort Sam Houston, the San Antonio Chamber of Commerce and a senator. The band was reassigned to the Army Medical Department Center School at Fort Sam Houston and their designation changed to the old 323rd Army Band (eliminated by military cutbacks in 1973). Master craftsmen from the National Park Service began renovations to the Band Building at Fort Sam Houston in October 1993, marking the 100th anniversary of its construction. The building is unique for two reasons: It is the only structure of its shape in the country and the only band building in the Department of Defense inventory. It was designed by famed San Antonio architect Alfred Giles and is listed on the National Register of Historic Places. The original structure included a belvedere roof (large gazebo) that was replaced. The roof sheltered band members while they played for post parades. The pyramid-shaped roof was blown off in the 1940s by a powerful gust of wind. The latest repairs were completed in 1994.