Up until the 1930s the interwar period between world war one and world war two the world of armor was rather silent, Then the U.S. cavalry adopted the M1 combat car to allow the cavalry units to move with speed and protection, it had a twin mounted 7.62 machine guns mounted in the turret which was latter replaced with one 37mm cannon. This tank however never saw combat. The M2 light tank was then manufactured in 1939 by the Rock Island Arsenal, it was one of the first tanks to incorporate sloped armor in the design. Though however it was later decided it was a majorly flawed with such a high profile and thin armor. There
The Armor Corps was finally formed in 1940 and Fort Knox was reassigned as an armor training base. Thus solidifying the need for armor in the military, thus also initiating a jump of improvements of tank design. One major one being the transition of moving from riveted armor to welded armor. Riveted armor had the issue of spalling when hit, Spalling is when the armor literally disintegrates and sends micro shrapnel into the tank. Other improvements included moving from the hull mounted gun design of the M3