Jim_Callahan said:Technically, they're a branch of the navy, though the separation of the chains of command is very high up (the Marine commandant reports to the secretary of the Navy). Many marine officers come from the naval ROTC program as well instead of the more specialized Marine corps ROTC.almostgold said:I know what you meant, but MASSIVE peeve of mine: Marines AREN'T the army. You're thinking 'military'. Army is a branch of the military. The USMC is another (better) branch.
But yeah, the three branches of the military in the US are Army, Navy, and Air Force and the Marine Corps falls under the purview of the second group, not the first.
Common misconception here: there are 5 branches (US Army, US Air Force, US Navy, US Marine Corps, US Coast Guard). The USMC is not under the command of the US Navy. Misconception comes because besides the "US Navy" (the military branch), there is an executive organization structure called the "Department of the Navy". Both the USMC and the USN (and the Coast Guard, in times of war, should the President or Congress decide) are components of the Department of the Navy. The Commandant of the Marine Corps does not report to the Chief of Naval Operations (the head of the US Navy). Both report to the Secretary of the Navy, who is a civilian.
To recap: US Navy =/= Department of the Navy. Department of the Navy is a civilian run oversight organisation. The USMC is not a branch of the 'Navy' (i.e., the military branch).