Ellis Island
During and immediately following World War II, Ellis Island was used to hold German merchant mariners and "enemy aliens"—Axis nationals detained for fear of spying, sabotage, and other fifth column activity. In December 1941, Ellis Island held 279 Japanese, 248 Germans, and 81 Italians removed from the East Coast. Unlike other wartime immigration detention stations, Ellis Island was designated as a permanent holding facility and was used to hold foreign nationals throughout the war. A total of 7,000 Germans, Italians and Japanese would be ultimately detained at Ellis Island. It was also a processing center for returning sick or wounded U.S. soldiers, and a Coast Guard training base. Ellis Island still managed to process tens of thousands of immigrants per year during this time, but many fewer than the hundreds of thousands per year who arrived before the war. After the war, immigration rapidly returned to earlier levels.
New York (state)
When the federal government assumed control, it established the Bureau of Immigration, which chose the three-acre Ellis Island in Upper New York Harbor for an entry depot. Already federally controlled, the island had served as an ammunition depot. It was chosen due its relative isolation with proximity to New York City and the rail lines of Jersey City, New Jersey, via a short ferry ride. While the island was being developed and expanded via land reclamation, the federal government operated a temporary depot at the Barge Office at the Battery.