Though it’s often overlooked today, during World War II, the United States held hundreds of thousands of enemy prisoners of war, and the country was unprepared for the influx, despite the fact that only weeks after the attack on Pearl Harbor, the government started detaining Japanese Americans and foreigners from Axis countries. Some camps, used for training Army recruits, were repurposed as prison camps, and the experience of building camps for the 120,000 Japanese and Japanese Americans was useful in building camps for the POWs. In addition to the Japanese, about 31,000 German, Japanese, and Italian residents were placed in camps.

At first, there were few POWs because it took months for the American military to get ready to participate in campaigns. The first POW was a Japanese sailor who’d survived the sinking of his midget submarine at Pearl Harbor. The first German prisoners were survivors of U-boats sunk off the American coasts. There were also a few hundred German and Italian merchant sailors on ships seized in American ports (these sailors were interned as enemy aliens, not POWs).

Soon, the prisoners came in waves. A sizable number came to the US at the request of Britain, which had too many prisoners and sent tens of thousands to Canada and the US. The first large number of enemy POWs captured by American forces came at the end of the North Africa campaign in May 1943, when the Allied forces trapped most of the vaunted Afrika Korps in Tunisia (then a French colony) and forced it to surrender. About 280,000 German and Italian troops surrendered. These were different from later prisoners; they tended to be volunteers, with many of them fervent Nazis (if German) and diehard Fascists (if Italian). They were generally confident of an ultimate German victory.