An elite force within an elite force? It was quite the radical idea over 70 years ago in the early years of World War II. But President Franklin Roosevelt had been captivated by the success of newly formed British commandos and their raids against the Germans (most notably the famous SAS). In 1942 the Naval forces of the United States saw the need for small groups of Marine infantry, landing swiftly in rubber boats or by landing craft, to operate behind Japanese lines in the islands of the South Pacific. FDR gave the order to create the units, and soon two battalions (roughly 800 men per unit) were formed. And the Commandant of the Marine Corps gave them their name. They were not commandos. They were "Raiders."
The First Battalion were commanded by Lt. Col. "Red Mike" Edson. The Second was Lt. Col. Evans Carlson's Battalion. Both men were fierce, dogged warriors, but they commanded differently. Edson went more by formal command structure, but in battle he was everywhere. In World War II he earned both the Medal of Honor and the Navy Cross. Carlson had observed the Chinese communist command structure and tactics against the Japanese, and believed their more casual observance of rank was best for guerrilla warfare. Carlson also changed basic infantry strategy to use 3 man "fire teams" (one man with a Tommy gun, one with a Browning Automatic Rifle, and one man with an M-1 Garand.
Edson's Raiders held off superior numbers of Japanese troops in charge after charge on Guadalcanal. Carlson's Raiders got on subs and raised Japanese troops on Makin Island. Tragically, when the Marines left the island, they left behind nine of their men. Those nine were captured by the Japanese and beheaded on Kwajalein Island.
But both battalions continued to battle it out throughout all of 1942 and 1943 in the Solomon Islands and New Georgia (near New Guinea). Even President Roosevelt's son James was a Raider, serving as a Lieutenant Colonel and earning the Navy Cross himself! But by 1944 the Marine Corps was stretched to its limits. And the admirals and generals never really liked the idea of an elite force within an elite force.
As successful as they were, the Marine Corps decided to stop wasting efforts on these smaller units, and they disbanded them. The Marines were sent to standard infantry regiments where they distinguished themselves in battle against the Japanese.
Today the Marines have their own special forces (once again), just like the other branches. One is called Marine Recon, and the other is MARSOC. In 2014 MARSOC was redesignated as the First Marine Raider Battalion, and allowed to wear the old Raider patch (a blue field with white stars and a white skull), in honor of their World War II brethren.