The soldiers spent months behind enemy lines, marching hundreds of miles through the tangled jungles and steep mountains of Burma as they battled hunger and disease between firefights with Japanese forces during their secret mission.

In February 1944, the American jungle fighting unit nicknamed Merrill's Marauders set out to capture a Japanese-held airfield and open an Allied supply route between India and China. Starting with 3,000 soldiers, the Marauders completed their mission five months later with barely 200 men still in the fight.

The journey of roughly 1,000 miles (1,610 kilometers) on foot was so grueling that fighting “was the easy part,” said Robert Passanisi, who at age 96 is among just nine known Marauders still known to be alive.

Now the Marauders, officially designated by the Army as the 5307th Composite Unit (Provisional), have been approved by Congress to be awarded its highest honor: the Congressional Gold Medal.

Passanisi enlisted his fellow surviving Marauders and the families of many who have died to begin lobbying for the honor four years ago. A final bill approved in September was sent Oct. 6 to the White House, where it awaits President Donald Trump's signature.

“After many years, all the sacrifices, and the suffering, are now finally recognized,” said Passanisi, of Lindenhurst, New York. “It makes you feel like it was all worthwhile.”

In 1943, President Franklin D. Roosevelt agreed to have the Army assemble a ground unit for a long-range mission behind enemy lines into Japanese-occupied Burma, now Myanmar. Seasoned infantrymen and newly enlisted soldiers alike volunteered for the mission, deemed so secret they weren't told where they were going.

Merrill's Marauders — nicknamed for the unit's commander, Brig. Gen. Frank Merrill — were tasked with cutting off Japanese communications and supply lines along their long march to the airfield at the occupied town of Myitkyina. Often outnumbered, they successfully fought Japanese troops in five major engagements, plus 30 minor ones, between February and August 1944.

Marauders spent most days cutting their way through dense jungle, with only mules to help carry equipment and provisions. They slept on the ground, and rarely changed clothes. Supplies dropped from planes were their only means of replenishing rations and ammunition. Malnutrition and the wet climate left the soldiers vulnerable to malaria, dysentery and other diseases.

“These guys were subsisting on one K-ration per man, per day,” said Christopher Goodrow, arms curator for the National Infantry Museum in Columbus, Georgia. "You’re talking about a can of tuna, some crackers, a chocolate bar and cigarettes."

At neighboring Fort Benning, the elite fighters of the Army's 75th Ranger Regiment consider themselves proud descendants of Merrill's Marauders, who are revered for their overall toughness.

“They’re in a class all by themselves when it comes to the things they endured,” Goodrow said.

The Marauders join more than 160 war heroes, military units and civilians awarded the Congressional Gold Medal for outstanding achievements dating back to the American Revolution. A single medal honoring the Marauders as a unit will be crafted and given to the Smithsonian Institution.

The medals are individually designed for each set of winners and can take more than a year before they’re ready to be presented.

Time isn’t on the Marauders’ side. Twenty of the unit’s members who were living when they began petitioning Congress for the medal in 2016 have since died, said Jonnie Melillo Clasen. Her father, Vincent Melillo, served in the unit and died in 2015.

Dozens of Marauders were awarded individual decorations after the war, from the Distinguished Service Cross to the Silver Star. The Army awarded the Bronze Star to every soldier in the unit, and Hollywood paid its respects in 1962 with the movie “Merrill's Marauders.”

Surviving members consider the congressional medal the highest honor they could receive as a unit.

“It was a hard job but we went in there and did our best,” said Gilbert Howland, 97, of Hamilton, New Jersey. “I just feel that the Marauders deserve it.”

As young corporal in charge of 16 Marauders manning two machine guns, Howland got wounded by artillery fire when their battalion was surrounded by Japanese fighters. While recovering at a hospital in India, Howland and other wounded Marauders received a desperate order to return to the fight.

The Marauders had captured the airfield that was their key objective, but Japanese forces had mounted an effort to take it back. The remaining Marauders were too few and too exhausted to hold it.

Howland rejoined his machine gunners, but the airfield was thick with mosquitoes and he soon came down with malaria. He remained at his post until he passed out with fever. He was evacuated on a stretcher and flown back to India, then sent home to the U.S.

“They we getting ready to discharge me," he recalled. “Then my mother said, `Why don’t you stay in? You put all this time into the Army.'”

So Howland re-enlisted. He served another 25 years, including combat tours in Korea and in Vietnam. He still says the Burma mission was the toughest of them all.

___

Bynum reported from Savannah, Georgia.

___

This story has been corrected to show that Vincent Melillo died in 2015, not 2007.