The flag of the newest branch to the US Armed Forces. 

The United States Air Force came into existence in 1947.  The distinctive color (flag) of the Air Force was established in 1951.  The flag background is a special shade known as “Air Force blue.” 

The design was based on the Army seal adopted in 1779 by the Continental Congress. It includes a cuirass (breast plate) that represents the Army defending the nation. There is also a liberty cap of the type used in the Roman Empire and a pike carried by certain military officers. Cannon, cannonballs, a mortar, powder flask, and a rattlesnake (such as appeared on some Revolutionary War flags) complete the design.

That flag, with vertical stripes, is still in use but it was not chosen by the Coast Guard when a ceremonial color was adopted in July 1951.  The United States coat of arms, dating from 1782, was displayed in the center of a white field and  instead of the usual colors the design featured the national red, white, and blue. 

The globe features the New World, site of most early Marine Corps military engagements. Red and gold were made the official colors of the Corps in 1925 and the current standard (flag) of the Corps was established in 1939. The scroll held in the beak of the eagle in this flag bears the Latin motto SEMPER FIDELIS (Always Faithful).

The flag of the US Navy shows a Revolutionary War vessel with the national flag, the naval pennant, and the rank flag of the commanding officer.  In the foreground is an American bald eagle with a large anchor behind it.  In the official seal the foreground showed some land.  However, when the flag was adopted the Secretary of the Navy insisted that only the ocean be represented, without any land area.