*Many European armeis, including the British, wore a simple rectangular side cap based on the style worn by the French. The new "overseas" cap, so named because it was only issued to U.S. forces serving in Europe, was adopted in 1917. It was compact enough to stuff into a pocket, was constructedf from olive drab wool as the winter service uniform, and it provided a uniform, soldierly appearance." (taken from internet, see IL.2006.31 for information and picture of cap). Inside sweat band is off white cotton.
*Hand printed ink head band: "C...Co.326 G. C. #1680823"