Field trousers with cotton satin lining adopted by the US Army in 1951. Around this time, the Army adopted the M-51 series set-up layered system as combat uniforms for cold regions. A wool field shirt and field trousers were worn over an undershirt and drawers, and a cotton field jacket and field pants were worn over them. All M-51s were loose-fitting to keep body heat in and keep out outside air, with consideration given to wearing them in cold regions. The cord loop on the inside of the waist is a detail for hooking the metal hooks at the ends of the suspenders.
