The olive drab "Cap, Wool, Knit, M1941" was standardized in early 1942, intended for wear under the M-1 Steel Helmet. Although the helmet liner had a webbing suspension system, soldiers liked having the extra padding and warmth of the wool cap.
Sgt. Hulon T. Farrell of Temple, Texas, 2nd Infantry Division, wearing a 'Cap, wool, knit, M1941' sets the range on a 105mm Howitzer as he receives instructions for a firing mission on the earphones. Photo taken in Midrum, Belgium. 22 January 1945.
The Cap, Wool, Knit, M1941 had a short visor and ear flaps that could be turned up against the side of the hat or worn down over the ears as needed for the weather. It was soft and could be folded into a pocket when not needed.
The wool cap was popular with the troops but officers thought it was slovenly. For unknown reasons it was nicknamed "beanie" and is also called a "jeep cap". The M-1943 Field Cap (developed as part of the layered M-1943 field jacket uniform system) superceded it toward the end of World War II.
The television series M*A*S*H made this World War II cap famous, although the setting of the show is supposed to be the Korean War. The jeep cap was worn in all the epiodes by the character Cpl. Walter "Radar" O'Reilly, the 4077th Mobile Army Surgical Hospital company clerk. The photo at right shows actor Gary Burghoff as Radar, with cap.
Perhaps because of Radar O'Reilly, the "Cap, Wool, Knit, M1941" continues to be manufactured and is available through many of the suppliers of military surplus or outdoor clothing. Generally it is called a "Jeep Cap" and is sold in the original military Olive Drab color or other commercial colors.
The watch cap, or stocking cap, was standard issue in the Navy and Coast Guard for rough weather use. The photo at right shows a helmsman and on the bridge of a Coast Guard cutter at sea in the North Atlantic during World War II. Issued in dark blue and black, the dense knit cap kept the head warm by itself or as an inner layer for the hood of foul weather gear. It was also worn under the liner of a steel helmet. The bottom could be folded up so the cap covered the top of the head (as in the photo, right), or folded down over the ears to cover them and the back of the neck. These useful caps were prized by some in the Army who could get hold of them since they were much warmer and more versatile than the M1941 wool knit cap.
After World War II
The M1941 knit cap was phased out, replaced by the Field Cap as noted above. The watch cap lives on and is in current use in all branches of the service. The current nomenclature is Cap, Enlisted Man's, Wool/Knitted, Blue 3346, US Navy with NSN 8405-01-006-1074. It has been issued in Black, Forest Green and Olive Drab under the same NSN.
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