Origin of The Historic M1941 US Army Jeep Cap

Origin of The Historic M1941 US Army Jeep Cap

By John Linden

Birthed under the name M1941 Wool Knit Cap but known as the famous and unforgettable “Jeep Cap”. The designed resembled a beanie with a built in brim. Originally made from wool but now out of acrylic. The Jeep Cap was immediately accepted by Pop Culture from its first reveal in 1942. Throughout the generations the Jeep Cap has changed names such as “Radar Cap” thanks to Radar O’Reilly from the hit show M*A*S*H to “Skull Cap” popularized by skateboarders in the early 2000’s and now preferred as sportswear. Without further ado, The Origin of The Historic M1941 US Army Jeep Cap.

Conception and Dismissal

February 1942 was the first issued Jeep Cap by the United States army to serve the GI’s during WW2. Its sole purpose was to provide extra warmth and padding under the heavy combat helmets.

Originally knitted with a six-stitch starfish pattern to support the webbing inside the helmets and fuzed with an extra layer of wool starting on the top center of the brim. GI’s had the ability to pull down the extra layer over their ears for extra warmth. Issued in 4 different sizes - small, medium, large, and extra large and made of Olive Darb Wool (Take a peak at a Green Olive to get an idea of color).

Although its design was to be worn under the heavy combat helmets the cap alone became a staple among the GI’s for its relaxed demeanor. Creating a dislike among many generals including General Patton stating its “slovenly” and “un-military” look. If you know anything about Patton he was extremely persuasive deeming him to always get his way. The Jeep Cap was phased out and replaced with the Standardized Field Cap as part of the new, layered U.S Army M-1943 Uniform.

The Jeep Cap is still manufactured by the U.S. Army with an updated look. The cap is now designed to fit loose and deep if the soldier would like to have it lower to provide warmth. Instead of using the original six stitch starfish pattern it uses a four stitch topping as most commercial beanies are today. Also the ability to choose from small to extra large is now obsolete. With modern materials that give elasticity we now have one size fits all. The Cap is manufactured in a darker shade of Olive Darb with more color selections like Navy Blue, and Black. Leaving the only thing true to the original Jeep Cap is the short brim. The new fashion of Jeep Caps are now labeled under “Cap, Knit Watch RN-93084”.

Pop Culture and The Jeep Cap

Some of you still recall the late and great TV Hit Comedy/Drama show M*A*S*H when it first aired, others remember it as reruns (myself included). Radar O'Reilly was regularly caught rocking the famed Jeep Cap. As the show grew in popularity so did the Jeep Cap being rebranded as a “Radar Cap”. History continued and M*A*S*H ended in 1983 after its 11 year run. Placing the Radar Cap on the back burner. The early 2000s mark the coming of age Millennials. Marking the return of the “Radar Cap” once again rebranded, this time as a “Skull Cap” being its heavy use among the skateboarders. Sine the rebirth of the Jeep Cap in the early 2000’s it has become a staple of wear. With growing sport companies like Nike and Underarmour remanufacturing under the “sportswear” category. You can find a Jeep Cap with commercial colors and in some cases with embroidery designs. Especially during seasonal times.


The “Jeep Cap” began its humble begins during a time of war, its sole purpose to keep GI’s warm. Throughout its life it had radical changes from smash hit comedy dramas to Millennial skateboarders who enjoyed crushing their skulls against concrete. Now used as sportswear and lounge wear. But like everything that is man made, it once had a purpose, may we never forget The Historic M1941 US Army Jeep Cap’s roots.

Featured Image Credit: CBS Television [Public domain], via Wikimedia Commons