The M4 Sherman, formally Medium Tank, M4, was the primary tank used by the United States during World War II. Thousands were also distributed to the Allies, including the British Commonwealth and the Soviet Union, via lend-lease. In the United Kingdom, the M4 was named after Union General William Tecumseh Sherman, following the British practice of naming their American-built tanks after famous American Civil War generals. Subsequently, the British name found its way into common use in the U.S.
The Sherman evolved from the Grant and Lee medium tanks, which had an unusual side-sponson mounted 75 mm gun. It retained much of the previous mechanical design, but added the first American main 75 mm gun mounted on a fully traversing turret, with a gyrostabilizer enabling the crew to fire with reasonable accuracy while the tank was on the move. The designers stressed mechanical reliability, ease of production and maintenance, durability, standardization of parts and ammunition in a limited number of variants, and moderate size and weight. These factors made the Sherman superior in some regards to the earlier German light and medium tanks of 1939-41, which the German Army still used through the later stages of the war (albeit in up-gunned and up-armored variants). The Sherman ended up being produced in large numbers and formed the backbone of most Allied offensives, starting in late 1942.
The original Shermans were able to defeat the relatively small German tanks such as the Panzer III and IV they faced when first deployed in North Africa. Later, they found themselves more evenly matched against the newer up-gunned and up-armored Pz.Kpfw. IV medium tanks. Shermans were often outmatched by the 45 ton Panther tank and wholly inadequate against the 56 ton Tiger I and later 72 ton Tiger II heavy tanks, suffering high casualties against their heavier armor and more powerful 88 mm L/56 and L/71 cannons. Mobility, mechanical reliability and sheer numbers, supported by growing superiority in supporting fighter-bombers and artillery, helped offset these disadvantages strategically. The relative ease of production allowed huge numbers of the Sherman to be produced. This allowed many divisions, even many infantry divisions, their own organic Sherman assets. Some infantry divisions had more tanks than German panzer divisions did. This was a huge advantage for the Americans.
Production of the Sherman was favored by the commander of the Armored Ground Forces, albeit controversially, over the heavier M26 Pershing, which resulted in the latter being deployed too late to play any significant role in the war. In the Pacific Theater, the Sherman was used chiefly against Japanese infantry and fortifications; in its rare encounters with much lighter Japanese tanks with weaker armor and guns, the Sherman's superiority was overwhelming.
Production of the M4 exceeded 50,000 units, and its chassis also served as the basis for numerous other armored vehicles such as tank destroyers, tank retrievers, and self-propelled artillery. Only the Soviet T-34 tank was produced in larger numbers during World War II.
The Sherman would finally give way to post-war tanks developed from the M26. Various original and updated versions of the Sherman would continue to see combat effectively in many later conflicts, including the Korean War, Arab-Israeli Wars, and Indo-Pakistani Wars into the late 20th century, against the T-34 and sometimes much more modern Soviet tanks.