The Major is wearing the uniform that reflects the 1924 changes in regulations. The main change was gilt buttons and insignia instead of the previous bronze color. The collar insignia indicates he is an Aide to a Major General. The 1920s also was the start of the practice of wearing ribbons on the uniforms. It was regulation in earlier years, but few wore them. The hat eagle also changed to gilt on this 1912 pattern visor hat.