Over eight decades ago, the US Navy made the historic capture of a Nazi U-boat during World War II. A treasure trove of vital German intelligence, the submarine's capture was top-secret. See inside ...

the US Navy made the historic capture of a Nazi U-boat during World War II. A treasure trove of vital German intelligence, the submarine's capture was top-secret. See inside the U-boat ...

a Union-side Civil War-era submarine prototype ... Thousands gathered for a peek inside the “infernal machine,” according to an account on the Navy & Marine Living History Association website.