There are a total of 26 World War 2 U.S Tanks. Tank development and doctrine were hampered before World War 2 by a decision to assign tanks to the infantry only and a reluctance on the part of the cavalry to give up the horse.
Light Tanks:
The M2s were the only operational US light tanks at the beginning of the war. The M2A4 was the sole among the four types which actually took part in combat, especially in the Pacific (like here, at Guadalcanal) with the USMC. It was removed from active duty in 1943. All the others, the pre-series M2A1, the M2A2 “duplex turret” or “Mae West”, and upgraded M2A3, were kept for training in the USA.
M1 Combat Car 113 built. This early development, along with the M2, was the basis of the M3-M5 “Stuart” lineage, which formed the backbone of US light tanks. The M1A2 was upgraded with a 37 mm (1.46 in) gun in 1940.
M2 Light Tank 700 built in four variants. Closely related to the M1A2. The most produced version was the M2A4, which saw service in the Pacific and Africa, before being replaced by the mass-produced M3. \ M3 Stuart 13,860 built. The M3 was a replacement for the M2, and was mass-produced, forming the core of the US light tanks during WW2.
M5 Stuart 8885 built. Based on the M3A3 with a modified hull and new Cadillac engine and transmission. Armor was reinforced, but the armament did not evolve.
M24 Chaffee 4731 built (and 720+ variants). Last WWII US light tank developed, it was better armored and armed, serving from 1944-45 until the late seventies. Medium Tank Medium tanks M2 medium tank 112 built. With the M2A1 wartime production series, this was the earliest US medium tank in service, in 1939. They were retained in the homeland as training machines.
M3 Lee/Grant3258 built. This long awaited model entered service as fast as possible with British units fighting in North Africa, through Lend-Lease. It was phased out in 1942, but served until 1945 in Asia. It was mobile, well armed and protected, but the high silhouette and spooners main gun were serious flaws. It was a transition model.
M4 Sherman 49,234 built. This mythical machine replaced the Lee/Grant and remains the most prolific tank of the western world. But it was a compromise and has some flaws as well, especially when facing German late tanks of 1943-45.
M26 Pershing Around 2000 built. Only 20 were deployed in Germany a few weeks before the end of the war. The development of this tanks started in 1942, but delays and modifications delayed the production until December 1944. It was well protected and fitted with a 90 mm (3.54 in). It was the base for Cold War US tank development, including the early T29 and T30. Heavy tanks As pragmatic planners, the US military never seriously envisioned heavyweight breakthrough machines, as tanks were traditionally attached to the cavalry. Speed and easy production were the main concerns at the start of WW2. After war experience in Europe started accumulating, the need for more penetrating power and increased protection came, advocating for all-better medium tanks, specialized tank-hunters and ultimately to the first wartime US heavy tank. The only U.S. Army super-heavy tank ever produced was the experimental T28.
M6 Heavy Tank 40 built in 1941. Considered obsolete by 1944, they never left home, serving as training machines, for propaganda movies and war bond shows.
Works cited- http://www.tanks.net/american-world-war-ii-tanks/index.html Book source: The Encyclopaedia of World War 2 A Political, Social, and Military History by: Dr. Spencer C. Tucker