I’ve been to that exhibit twice in my life...once in junior high school when the U-Boat was sitting outside the Museum of Science and Industry in Chicago (in the snow and ice), and again maybe 7-8 years ago when the (very nice) exhibit had been moved inside. Just don’t remember a lot about it.
Per Wiki...
“In her uniquely unlucky career with the Kriegsmarine, she had the distinction of being the “most heavily damaged U-boat to successfully return to port” in World War II (on her fourth patrol) and the only submarine in which a commanding officer took his own life in combat conditions (on her tenth patrol, following six botched patrols).[5]
She was one of six U-boats that were captured by Allied forces during World War II. She was captured on 4 June 1944 by United States Navy Task Group 22.3 (TG 22.3). All but one of U-505’s crew were rescued by the Navy task group. The submarine was towed to Bermuda in secret and her crew was interned at a US prisoner-of-war camp where they were denied access to International Red Cross visits. The Navy classified the capture as top secret and prevented its discovery by the Germans. Her codebooks, Enigma machine, and other secret materials found on board helped the Allied codebreakers.[6]
In 1954, U-505 was donated to the Museum of Science and Industry in Chicago, Illinois. She is now one of four German World War II U-boats that survive as museum ships, and, along with U-534, just one of two Type IXCs still in existence.”
Well worth a visit.
Yeah, well, they didn't want the Germans changing their naval codes so close to the invasion.