Olive Drab Cotton Field Jacket (also known as OD Cotton Field Jacket and, unofficially, Parsons Jacket, M1938 or M1941) is a field jacket used by US Army soldiers, most famously during the beginning of World War II. In 1941 it started to be phased in as a replacement for the wool four pocket service coat of World War I, but around 1943 it was replaced in turn by the improved M1943model. Due to wide adoption, the M1941 is usually recognized as a symbol of the World War II American G.I.. The jacket was made in a light shade of olive drab called OD number 3.