The "jeep cap" was first issued by the United States Army in February 1942 during World War II; the purpose of the jeep cap was to be worn underneath the heavy combat helmets to offer soldiers both extra padding, and warmth.
The jeep cap was originally knitted close to the head, with a six-stitch "starfish pattern" on top (supposedly to support the webbing suspension inside the helmets), with a cuff coming out like a V from the top centre of the brim, and around the rest of the cap, which soldiers could pull down over their ears for even more warmth. Although made specifically for wear under the steel pot helmet, the cap alone grew to be very popular with soldiers for its casual and relaxed look, and was often worn on its own.
The cap was usually only issued to enlisted men, however, officers (General Patton in particular) despised the cap for its "slovenly" and "un-military" look, and it was eventually phased out and replaced with the standardized field cap, as part of the newer, layered U.S. Army M-1943 Uniform.
Unusual dead stock from the 1970s.