On June 4, 1944 the German submarine U-505 was captured by Allied ships. This was the first German sub to be captured. All other subs were either scuttled or blown up by the German crews to avoid capture. For years the Americans wanted to capture one of the subs to study the technology and hopefully secure one of the German Enigma code machine.
The crew of the USS Chatelain depth charged and then boarded the German sub securing it from sinking. The sub was towed from the coast of West Africa to Bermuda. The crew of the U-505 were sent to POW camps in the US and kept apart from all other German prisoners to keep the sub capture secret.
After the was, the sub was eventually towed to Portsmouth, NH where it sat for many years eventually ending up in the Museum of Science and Industry in Chicago.