The Sheridan took shape in the late 1950s. February 1957 saw the beginning of an ambitious project, the next step in U.S. tank creation, with the work of the Ad Hoc Group on Armament for Future Tanks or Similar Combat Vehicles. The Army Historical Foundation reports that one objective of this work was to develop an “armored reconnaissance/airborne assault vehicle.”
From this designation alone, it seems clear that such a vehicle was to be designed with three priorities in mind: agility and relative speedy, versatility enough to be dispensed where it’s needed, and boasting sufficient offenses of its own. It’s difficult to deny that the Sheridan, which topped out at a respectable 43 mph, had all these qualities.
Utilizing a main body fashioned from aluminum, General Motors was able to keep the tank’s weight down to approximately 15 tons. As befits the light tank designation, this made the machine so (relatively) light that it was possible for the military to air-drop it into theaters where it was needed.
The Sheridan combined these traits with an XM81, a unique weapon system that could fire a range of devastating ammo. The likes of the Shillelagh missile and M409 HEAT missiles ensured it was a huge threat to tanks in much larger packages and opposing infantry alike. On paper, in particular, it was a sophisticated and impressive American tank, but it also had some major shortcomings that tarnished its reputation.