The M1 Abrams is the principal military combat tank of the United States Army and Marine Corps. In use since the 1980s, it is designed for ground warfare and is heavily armed and armored. It is also highly maneuverable. The M1 Abrams is named after General Creighton Abrams, former Army chief of staff and commander of the Armed Forces in Vietnam from 1968-1972.

The tank was designed by Chrysler Defense (now General Dynamics Land Systems) during the 1970s, and was the first vehicle to utilize Chobham armor, a composite ceramic armor far superior to any armor used up to that point. Chrysler used a powerful multi-fuel turbine engine and incorporated a separate inner storage area for ammunition, designed to blowout to protect the four-man crew. The main armament of the original model tank was a 105 mm rifled gun; secondary armaments consisted of three machine guns. The M1 Abrams is one of the heaviest tanks in service (54 metric tons).

The most interesting characteristic of this tank series, the M1, M1A1 and M1A2, is that the tanks are not discarded or sold, but rather continuously maintained, upgraded, and improved.  Ten thousand tanks have been built at the Lima Army Tank Plant (since 1980) or the Detroit Arsenal Tank Plant (1982-1996). The tanks have become progressively heavier over the series from 54 to 65 metric tons. The final version utilizes depleted uranium mesh reinforced armor. The tank holds 500 gallons of fuel and can maintain speeds of 45 mph, or 30 mph off-road. The main gun can shoot 8,200 ft., a great advantage in the field against Soviet tanks which shot 6,600 ft.

Improvements to the M1 Abrams over the years include, among others, better armament and electronics. Before the Persian Gulf War, the tank was adapted for increased firepower, and improved protection from nuclear, biological, and chemical agents. After the war, weapon sights and the fire control unit were upgraded, and a friendly fire identification unit was installed. In 2003, the tanks experienced urban combat resulting in further modifications. During Desert Storm, some tanks were fortified with armor while in the field.

The M1A1 version of the tank includes a thermal viewer for the commander, upgraded navigation equipment, a weapon station, and digital controls and displays. Digital maps, and an improved cooling system were also added. Later improvements upgraded the weapon station, added color displays, installed a new operating system, enhanced side and front armor, and upgraded the transmission. Standardized parts were used on the tanks with coordination between the Army and the Marines to best utilize equipment and make repairs simpler.

The M1 Abrams, the M1A1, and the M1A2 have seen action in the Persian Gulf War, Desert Storm, the war in Afghanistan, the Iraq war, the Iraqi Civil War, and the Intervention in Yemen, and are expected to see more action as the tanks are maintained and adapted with an ongoing attitude of permanence.