Built in 1942 by the T.L. James Company under U.S. Army Corps of Engineers supervision, Camp Ruston was originally meant to intern Japanese Americans. That plan was abandoned, and the camp briefly served as a training center for the Women's Army Corps, with approximately 2,000 WACs passing through before the barracks were cleared for an entirely different purpose. In August 1943, the first 300 prisoners arrived, veterans of Field Marshal Erwin Rommel's elite Afrika Korps. By October, the population had swelled to 4,315, making it one of the largest POW camps in the country. The prisoners were remarkably diverse: Germans, French, Austrians, Italians, Czechs, Poles, Yugoslavs, Romanians, and over 100 Russians. Camp records describe several soldiers with what they called "Mongol features" who required halal diets. They turned out to be Chechens.

One group of captives was hidden from everyone, including the International Red Cross. In late July 1944, the 56 surviving officers and crew of the German submarine U-505 were brought to Camp Ruston and locked in an isolated compound in the northeast corner. Their capture had delivered secret German naval codes into Allied hands, and no one could know they were alive. Captain Harold Lange's log of the U-505's final voyage, now held at Louisiana Tech University, reveals a telling detail: his last entry, describing a calm evening, was pre-written before the actual capture earlier that day on June 4. The museum at Chicago's Museum of Science and Industry, where the U-505 now sits, long believed the crew had been held in Bermuda. It was not until researcher Vincent Spione shared declassified National Archives records in 1998 that the museum corrected its exhibit to reflect the crew's true imprisonment at Camp Ruston.

Daily life at Camp Ruston was paradoxically decent. A Luftwaffe prisoner later said that compared to conditions in Germany, the camp was "like a vacation." Prisoners ate the same food as their guards, organized an orchestra, formed a theater troupe, built a library, and even broadcast a concert on local radio station KWKH. Enlisted men picked cotton, felled timber, and built roads across north Louisiana, paid in scrip redeemable at the camp canteen. In 1944, the War Department began educating POWs in democratic values, using books from the library of Louisiana Polytechnic Institute. Many prisoners later credited this instruction as the seed of democracy in postwar Germany. Of the 34 prisoners who escaped and stayed free for more than 24 hours, only one was never caught. Charly King, born on Christmas Day 1921, spoke fluent German, English, and Spanish. He slipped out of a branch camp at Bastrop, made his way to neutral Mexico, survived a serious truck accident, and eventually caught a ship back to Germany. The FBI searched for him for years.

Perhaps the most remarkable individual story belongs to Ensign Karl Ernst Pfaff of U-boat 234, a submarine bound for Japan carrying rocket plans, a crated jet plane, and over 500 kilograms of uranium oxide. When U-234 surrendered seven days after Germany's capitulation, Pfaff helped the Americans locate the uranium hidden in a false wall around the conning tower. He was separated from his crew and sent to Camp Ruston, eventually gaining American citizenship. The last prisoners left the camp on February 3, 1946. The site became a tuberculosis sanatorium, then a facility for the mentally disabled. Today, much of the former camp is a livestock facility for Louisiana Tech University. Only a few dilapidated hospital buildings remain, placed on the National Register of Historic Places in 1991. But the human connections outlasted the structures. Former POWs returned to Ruston for a 40th-anniversary reunion in 1984 and again for a symposium in 1995, confirming friendships forged during wartime in the Louisiana pines.