The M551 Sheridan Tank (or simply Sheridan) is a light tank developed during the 1960s and in service with the U.S. Armed Forces in 1969 to 1996. Officially known as the Armored Reconnaissance/Airborne Assault Vehicle M551. The Sheridan saw extensive use during the later years of the Vietnam War. Later on, it was not used very often by U.S. forces, only a few during the Panama conflict in 1989-90 and during the Gulf War of 1990-91.