The M3 and M5 were the culmination of American tank development of the 1930s. By the time of the outbreak of the Second World War, they were approaching obsolescence, as tank forces in Europe were shifting from light to medium tanks as the main element of their armored forces.
They first entered combat in the fall of 1941 in the Western Desert with the British Army, the Stuart quickly showed that it was inadequate in tank fighting. That story repeated itself a year later when the US Army confronted the Afrikakorps in Tunisia. It was later moved to secondary missions such as reconnaissance.
The M3 and M5 proved more suitable in the Pacific theater than in Europe, and fought successfully in many of the major battles including Guadalcanal, Tarawa, Peleliu, Saipan and Burma.
The Stuart went through many modifications from its beginning in the early 1930s as the T1 Combat Car, M1A1 Combat Car, M2 Combat Car, M2A1 Light Tank, M2A2 Light Tank, M2A3 Light Tank, M2A4 Light Tank, M3 diesel, M3 gasoline, M3A1 diesel, M3A1 gasoline, M3A3, M5, M5A1 and M8 HMC.
As outlined in FM 2-30 Cavalry Reconnaissance Mechanized::
Sec 2, F – The light tank company is the support element of he squadron. The company provides combat power to overcome minor opposition. It can be employed most effectively in combat as a unit, supported by the fire of assault guns to neutralize weapons.
4. (2) – The light tank is the principal offensive weapon of the squadron. The roll of the tank is destructive of personnel. Armor provides protection against small-arms fir. The light tank has good road speed and excellent mobility across country.
A few photos of Company F from my collections.