The Marine Corps has had precedence over the Navy since 1921 because the Marine Corps has been very consistent in citing its origins as the legislation of the Continental Congress that established the Continental Marines on 10 November 1775. In contrast, the United States Navy until 1972 gave various responses to the question of when it was founded, often citing legislation dating from its reestablishment in the 1790s.
Set Since the 1790s
At the time the order of precedence of the U.S. services was established, the Navy was using the dates from the 1790s, as its founding, and hence was viewed as a younger service than the Marine Corps. Despite several efforts to reverse the Marine Corps/Navy order of precedence in recent years, it has not occurred.
In fact, the Continental Navy was created before the Continental Marines. On 13 October 1775 Congress enacted the first naval legislation providing for the outfitting of two warships. This marked the beginning of the Continental Navy, the forerunner of the United States Navy. Almost one month later, 10 November 1775, as an extension of that naval legislation, Congress resolved that "two Battalions of marines be raised."
Following the Revolutionary War, both services went into abeyance. When they were reestablished in the 1790s, the reestablishment of the United States Navy preceded the reestablishment of the Marine Corps.
Shifting the Navy's Birthday
An order by the Marine Corps Commandant in 1921 designated 10 November 1775 as the birthday of the Marine Corps. Over the years, the U.S. Navy cited two other possible dates as founding events, the legislation of 27 March 1794, "to provide a naval armament," authorizing the construction of six frigates under the War Department, and the act of 30 April 1798, which established the Department of the Navy.
Despite the existence of these alternatives, the U.S. Navy for fifty years celebrated "Navy Day" on 27 October, as proposed in 1922 by the New York Navy League, in honor of President Theodore Roosevelt's birthday. The Navy had no officially recognized birthday until 1972, when Admiral Zumwalt, Chief of Naval Operations, with the advice of Vice Admiral Edwin B. Hooper, Director of Naval History, authorized observance of 13 October as the Navy Birthday.