Merrill’s Marauders, officially named the 5307th Composite Unit (provisional), was a United States long range penetration special forces unit in the South-East Asian Theater of World War II which fought in the Burma Campaign. The unit became famous for its deep-penetration missions behind Japanese lines, often engaging Japanese forces superior in number. Along with six Ranger Battalions, they are considered the only World War II-era Army light infantry unit comparable to the United States Army Rangers.

Myitkyina and the end

On May 17, 1944, after a grueling 65-mile march over the 6,000-foot Kumon Mountain range (using mules for carrying supplies) to Myitkyina, approximately 1,300 remaining Marauders, along with elements of the 42nd and 150th Chinese Infantry Regiments of the X Force, attacked the unsuspecting Japanese at the Myitkyina airfield.^[26] The airfield assault on May 17, 1944 was a complete success; however, the town of Myitkyina could not immediately be taken with the forces on hand. An initial assault by elements of two Chinese regiments was repulsed with heavy losses. NCAC intelligence staff had once again badly underestimated Japanese troop strength in the town^[27], which had steadily been reinforced, and now possessed a garrison of some 4,600 well-armed and fanatical Japanese defenders.^[28][29] Weakened by hunger^[30], the 5307th continued fighting through the height of the monsoon season, worsening the situation; it also transpired that the area around Myitkyina had the largest reported incidence of scrub typhus, which some Marauders contracted after sleeping on infected areas of untreated^[31] earth or grass.^[32] Racked with bloody dysentery and fevers, sleeping in the mud, Marauders alternately assaulted, then defended in a seesaw series of brutal conventional infantry engagements with Japanese forces.^[33] In a 1945 interview, Captain Fred O. Lyons, a Marauder officer, related the nature of the struggle:

" By now my dysentery was so violent I was draining blood. Every one of the men was sick from one cause or another. My shoulders were worn raw from the pack straps, and I left the pack behind...The boys with me weren't in much better shape...A scout moving ahead suddenly held his rifle high in the air. That meant Enemy sighted...Then at last we saw them, coming down the railroad four abreast...The gunner crouched low over his tommy-gun and tightened down. Then the gun spoke. Down flopped a half-dozen Japs, then another half dozen. The [Japanese] column spewed from their marching formation into the bush. We grabbed up the gun and slid back into the jungle. Sometimes staggering, sometimes running, sometimes dragging, I made it back to camp. I was so sick I didn't care whether the Japs broke through or not; so sick I didn't worry any more about letting the colonel down. All I wanted was unconsciousness."^[34]

After reinforcement by an airlanded Chinese army division, the town finally fell to the Allies on August 3, 1944. The Japanese commander escaped with about 600 of his men; 187 Japanese soldiers were captured, and the rest, some 3,800 men, were killed in combat.

In their final mission, the Marauders suffered 272 killed, 955 wounded, and 980 evacuated for illness and disease; some men later died from cerebral malaria, amoebic dysentery, and/or scrub typhus^[35]. Somewhat ironically, Marauders evacuated from the front lines were given jungle hammocks with protective sandfly netting and rain covers in which to sleep, equipment which might have prevented various diseases and illnesses had they been issued earlier in the campaign.^[36] The casualties included General Merrill himself, who had suffered a second-heart attack before going down with malaria. He was replaced by his second-in-command, Colonel Charles N. Hunter, who later prepared a scathing report on General Stilwell's medical evacuation policies (eventually prompting an Army Inspector General investigation and congressional hearings).^[37][38] By the time the town of Myitkyina was taken, only about 200 surviving members of the original Marauders were present. A week after Myitkyina fell, on August 10, 1944, the 5307th was disbanded with a final total of 130 combat-effective officers and men (out of the original 2,997). Of the 2,750 to enter Burma, only 2 were left alive who had never been hospitalized with wounds or major illness.^[39]

In slightly more than five months of combat, the Marauders had advanced 750 miles through some of the harshest jungle terrain in the world, fought in 5 major engagements (Walawbum, Shaduzup, Inkangahtawng, Nhpum Ga, and Myitkyina) and engaged in combat with the Japanese Army on thirty-two separate occasions, including two conventional defensive battles with enemy forces for which the force had not been intended nor equipped. Battling Japanese soldiers, hunger, fevers, and disease, they had traversed more jungle terrain on their long-range missions than any other U.S. Army formation during World War II.

The men of the Merrill's Marauders enjoyed the rare distinction of having each soldier awarded the Bronze Star. In June 1944, the 5307th Composite Unit (provisional) was awarded the Distinguished Unit Citation:

The unit must display such gallantry, determination, and esprit de corps in accomplishing its mission under extremely difficult and hazardous conditions as to set it apart and above other units participating in the same campaign.

On 10 August 1944 the Marauders were consolidated into the 475th Infantry. On 21 June 1954 the 475th Infantry was re-designated as the 75th Infantry; thus Merrill's Marauders is the parent of the 75th Infantry Regiment, from which descended the 75th Ranger Regiment.

The commander of the 2nd battalion of the Marauders, Colonel George A. McGee was inducted into the Ranger Hall of Fame for extraordinary valor and exemplary service.