America was entering a new century. Fresh from defeating Spain in the Spanish-American War, the young country was assuming its new position in the old world order. Filled with confidence and economic strength, the United Sates looked towards the future with the many opportunities and changes presented to it and its people. These changes also applied to the United States Army and its uniforms, in particular, the uniform cap and its insignia. Presented here are those changes in US Army cap insignia during the twentieth century. Shown in photographs and words drawn from US Government and US Army archives, with dimensions and close-up images of insignia, a thorough history can now be revealed!