These brackets were used to hold a training version of the HVAR (High Velocity Aircraft Rocket), also called the Holy Moses. It was an effective air-to-surface missile. The U.S. Navy used it against land and sea targets in the European and Pacific theaters in World War II and during the Korean War. Carried by such Navy airplanes as the F4U Corsair, HVARs also equipped some Army Air Forces aircraft. About a million rockets were produced.
The U.S. Marine Corps transferred these brackets to the Smithsonian along with the HVAR rocket to which they were attached.