The M551 Sheridan is often referred to as a light tank, but in actuality it was an armored reconnaissance/airborne assault vehicle. The M551 was designed to be a lightweight, amphibious, air-droppable vehicle armed with a massive 152 mm gun that doubled as a rocket launcher. The gun launcher was designed to fire the MGM-51 Shillelagh antitank missile, or 152 mm conventional rounds with a combustible cartridge case. The vehicles saw extensive use in Vietnam, Operation Just Cause in Panama (where they saw their only combat air drop), and Operations Desert Shield and Desert Storm.  The Sheridan ended its service with the US Army masquerading as Soviet Bloc vehicles at the National Training Center. Through dozens of archival as well as detailed photographs of some of the finest extant examples of these vehicles, the Sheridan is explored, and its history explained. Part of the Legends of Warfare series.