I am not entirely certain, but I think the M2 medium was considered obsolete before the US entered the war, because of military events across the Atlantic. I think it was used only for armored training inside the US.
The US built Sherman medium tank.
The medium tank T20 was designed in the United States during the second world war. This tank weighs about 29.83 metric tons and is 5.7m in length, 3m in width, and 2.44m in height.
The M3 Lee (Grant), M4 Sherman, and the M26 Pershing (reclassified as a heavy tank, and then reclassified again as a medium tank).
World War 1 saw the introduction of the tank and of aircraft.
The M4 Sherman, formally Medium Tank, M4, was the primary tank used by the United States during World War II. It was also distributed to the Allies via lend-lease. Evolved from previous medium and light tanks, it was the first American medium tank with the main gun mounted on a fully traversing turret.Production of the M4 medium tank exceeded 50,000 units and its chassis served as the basis for numerous other armored vehicles such as tank destroyers, tank retrievers, and self-propelled artillery. Only the Soviet T-34tank was produced in larger numbers.
to killed brits in world war one
The tank was well in use by the start of WWII. They were first developed by the French and British during the First World War.
* IS tank, a Soviet heavy tank in World War II
The allied commonly used Medium type tanks. They did use few Heavy Tier tanks but it was mainly the Soviets which produced a substantial amount of Heavy type tanks.
World War One.
The best tanks are the "blooded" ones. 1. WWI's best tank was the British Mark series. 2. WWII's best tank is a toss up between the Soviet (Russian) T-34 and the US M4, both were medium tanks. 3. Korean War's best tank was the US M46 Patton (a modified Pershing M26 medium tank). 4. Vietnam War's best tank was the US M48 Patton medium tank; the last of the Patton series of tanks. 5. Post Viet War's best tank is the battle proven M1 Abrams.
Although the British Mark I tank was the first tank, it was not until the production of the Mark V in 1917 that the tank was more nimble and safe for practical war use.