In August 1942, President Franklin D. Roosevelt and Prime Minister Winston Churchill agreed to create an American ground unit whose sole purpose would be to engage in a "long-range penetration mission" in Japanese-occupied Burma. This mission would consist of cutting Japanese communications and supply lines and otherwise throwing the enemy's positions into chaos. It was hoped that this commando force could thus prepare the way for Gen. Joseph Stillwell's Chinese American Force to reopen the Burma Road, which was closed in April 1942 by the Japanese invaders, and once again allow supplies and war material into China through this route.
Within the military, a type of "Help Wanted" ad was put up with the president's authority, an appeal for applicants to participate in a "dangerous and hazardous mission." About 3,000 soldiers volunteered from stateside units to create what was officially called the 5307th Composite Unit, code named "Galahad." It would go into history as Merrill's Marauders, after Brig. Gen. Frank Merrill, their commander.
Brigadier General Merrill trained his men in the art of guerrilla warfare in the jungles of India, for secrecy's sake. The commando force was formed into six combat units--Red, White, Blue, Green, Orange, and Khaki--with 400 men in each (the remaining 600 men or so were part of a rear-echelon headquarters that remained in India to coordinate the air-drops of equipment to the men in the field).
The Marauders' mission began with a 1,000-mile walk through dense jungle, without artillery support, into Burma. On February 24, 1944, they began their Burmese campaign, which, when done, consisted of five major and 30 minor engagements with a far more numerous Japanese enemy. They had to carry their supplies on their backs and on pack mules, and were resupplied only with airdrops in the middle of the jungle. Merrill's Marauders succeeded in maneuvering behind Japanese forces to cause the disruptions necessary to throw the enemy into confusion. They were so successful, the Marauders managed even to capture the Myitkyina Airfield in northern Burma.
When their mission was completed, all surviving Merrill's Marauders had to be evacuated to hospitals to be treated for everything from exhaustion and various tropical diseases to malnutrition or A.O.E. ("Accumulation of Everything"). They were awarded the Distinguished Unit Citation in July 1944, which was re-designated the Presidential Unit Citation in 1966. Every member of the commando force also received the Bronze Star, a very rare distinction for an entire unit. Merrill remained in the Far East and was made an aide to General Stillwell.