On 4 June 1944, a hunter-killer group of the United States Navy captured the German submarine U-505. This event marked the first time a U.S. Navy vessel had captured an enemy vessel at sea since the nineteenth century. The action took place in the Atlantic Ocean, in Latitude 21-30N, Longitude 19-20W, about 150 miles off the coast of Rio De Oro, Africa.
… Alerted by American cryptanalysts, who–along with the British–had been decrypting the German naval code, the Guadalcanal task group knew U-boats were operating off the African coast near Cape Verde. They did not know the precise location, however, because the exact coordinates (latitude and longitude) in the message were encoded separately before being enciphered for transmission. By adding this regional information together with high-frequency direction finding fixes (HF/DF)–which tracked U-boats by radio transmissions–and air and surface reconnaissance, the Allies could narrow down a U-boat’s location to a small area.
Fifty eight crew members were taken out of the submarine and sent to a POW camp in Ruston, Louisiana. In late 1954, Chicago acquired the submarine from the US government and installed it in the Museum of Science & Industry. The gutted interior of the submarine was refurbished with parts donated by German manufacturers. Their rationale: “We are sorry that you have our U-boat, but since she’s going to be there for many years, we want her to be a credit to German technology.”