OFFICER INSIGNIA OF GRADE
1. The method of identifying Colonels was initially established by General Washington on July 23, 1775 when he stated: " the field officers may have red or pink colored cockades in their hats, ". Although there is evidence that colonels wore the eagle as rank insignia in 1829 when they transferred the gold or gilt eagles that decorated their hat cockades to their collars. In 1832, gold eagles were authorized for infantry colonels because they were placed on silver epaulettes and silver eagles to be placed on gold epaulettes were authorized for all other colonels.
2. In 1851, the silver epaulettes for infantry was abolished and all epaulettes became gold. As a result, all colonel insignia of grade became silver. The 1851 regulation included illustrations which show the embroidered eagle on the shoulder strap faced the arrows while the eagle worn on the epaulettes faced the olive branch. Apparently due to the lack of specifications, the direction of the eagles head depended upon the manufacturer.
3. Metal insignia was authorized to be worn on the khaki blouse in 1902. The colonels insignia was described as a silver spread eagle. There is no reference as to the direction of the eagles head nor are there illustrations. The 1917 uniform specifications and regulations describe the insignia as a metal silver spread eagle, 3/4 inch high and 2 inches between the tips of the wings. It was worn on the shoulder loop, beak to the front, and on the right collar of the shirt with the eagles beak to the front. In 1921, the size of the eagle was reduced from 2 inches to 1 1/2 inches between the tips of the wings. The height of the insignia remained unchanged at 3/4 inch.
4. In 1926, the insignia was made in pairs with the head of the eagle facing to the front when worn. This was the first reference to the insignia being made in pairs. To do this, the eagles head was reversed on one insignia the insignia worn on the right shoulder had the eagles head facing the laurel branch. On the left shoulder, the eagles head faced the arrows. The insignia with the eagles head facing the arrow became known by the term "war eagle".
5. In 1951, the insignia was redesigned so that the eagles head faced the laurel branch on both the left and right shoulder insignia with the arrows to the rear on both insignia.
6. The so called "war eagle" is no longer authorized for wear on the uniform.
Information Courtesy of U.S. Army