One of the most noticeable changes in the Marine Corps uniform at the outset of World War II was the transition from the M1917A1 helmet reminiscent of World War I to the familiar M1 helmet of World War II, Korea, and Vietnam. At the outbreak of World War II, Marines were wearing a modernized version of the helmet first introduced to Marines serving in France during World War I. The American M1917 helmet was nearly identical to the British “Brodie Pattern” helmet. In 1939, this helmet was superseded in the Marine Corps by the improved M1917A1 helmet (as shown below, worn by men of the 6th Marines in Iceland). Helmet M1 left, and the Helmet M1917A1, right... The padded leather liner and two-piece canvas chinstrap of this updated version of the “tin hat,” as it was then called made it far more comfortable and sturdier than its predecessor. The steel helmet shell remained the same. In the Marine Corps, the helmet was worn both with and without insignia and, while most Marines wore the helmet in the rough olive drab paint, some units, most notably those in China, burnished, waxed, and polished theirs. Less than two years after the Marine Corps adoption of the M1917A1, a U.S. Army research team at Fort Benning under of Major Harold G. Sydenham, began working on a new design for a two-piece helmet which offered far more protection for the wearer. Adopted by the government as the M1 helmet on 9 June 1941, the Hadfield manganese steel helmet was first made by the McCord Radiator Company of Detroit, Michigan, while the fibre liner was manufactured by the Hawley Products Company. At the suggestion of General George S. Patton, the liner’s suspension system was patterned after a design by John T. Riddell that was used in contempory football helmets. The new helmet was issued to the Marine Corps in the spring and early summer of 1942 and, by the time of the Guadalcanal campaign later that summer, had all but supplanted the old “dishpan” helmet.