German submarine U-505 was captured intact by the U.S. Navy off West Africa in 1944 and is now displayed in Chicago.
The capture occurred on 4 June 1944, when a U.S. Navy hunter-killer task group attacked U-505 near the coast of French West Africa. American sailors boarded the damaged submarine before its crew could scuttle it, securing codebooks, charts, and an Enigma machine. The intelligence helped Allied efforts to understand German naval communications.
U-505 was a Type IXC submarine commissioned in 1941. After capture, the Navy secretly operated it in the Atlantic under the name USS Nemo. Its existence remained classified until after World War II, partly because revealing the capture could have alerted Germany that its naval codes were compromised.
In 1954, U-505 was transferred to the Museum of Science and Industry in Chicago. It is one of the few surviving German U-boats and a major museum example of a World War II submarine.