Notes
This is likely a U.S. Model 1912 Officer's Service Cap. Designed to provide officers with a more practical field cap, it was softer, shorter brimmed, and more compact than earlier officer caps. It was made from lightweight gabardine or wool, with drab coloring that replaced the conspicuous blue of its predecessors. The hat was widely worn behind the front lines during World War I, but was often substituted for simple overseas caps in combat zones as the latter were more compatible with steel helmets.