Shoulder patches are more than just fashion. The use of the shoulder patches began during the American Civil War, when the Union Army started using cloth patches. During World War I, General Pershing authorized the use of shoulder patches for the American Expeditionary Force in France. During World War II, almost all of the US Army was officially using shoulder patches. These patches however, were not called patches in the official language. They were known as "shoulder sleeve insignias." While the British use of shoulder patches was primarily to help identify units, the American saw these as actual insignia.

Shoulder patches are usually multi-colored that are worn at the top of the left sleeve. The symbols contained within these patches were varied and consists of heraldic designs, visual references to the home state, independent units, or a punning play on words. There was also a selection of color in the shoulder patches that were based on specific organizations. For example, the Signal Corps used the colors orange and white and the insignia was cross signal flags and farming torch while the Coast Artillery used the scarlet color and the insignia of crossed cannon and shell in red oval. Apart from carrying numbers that denote the unit or the brigade, shoulder patches also carry certain terms that are usually abbreviations. Thus "AM" means "Airmobile" and "ASH" means "Assault Support Helicopter."

Usually military shoulder patches can be embroidered. Patches can be both 3 dimensional or flat, largely depending on the particular type of artwork. Advances in modern embroidery technology facilitate the incorporation of a lot of details. During World War II, patches were either machine-embroidered onto khaki cotton cloth or bullion-embroidered, a style that was changed with time. Shoulder patches are not merely ornamental decoration. They add a good lot of information on to the military uniform.