On August 5, 2002, the rusty iron gun turret of the U.S.S. Monitor broke from the water and into the daylight for the first time in 140 years. The ironclad warship was raised from the floor of the Atlantic, where it had rested since it went down in a storm off Cape Hatteras, North Carolina, during the Civil War. Divers had been working for six weeks to bring it to the surface.

Nine months before sinking into its watery grave, the Monitor had been part of a revolution in naval warfare. On March 9, 1862, it dueled to a standstill with the C.S.S. Virginia (originally the U.S.S. Merrimack) in one of the most famous moments in naval history—the first time two ironclads faced each other in a naval engagement. During the battle, the two ships circled one another, jockeying for position as they fired their guns. The cannon balls simply deflected off the iron ships. In the early afternoon, the Virginia pulled back to Norfolk. Neither ship was seriously damaged, but the Monitor effectively ended the short reign of terror that the Confederate ironclad had brought to the Union navy.

Designed by Swedish engineer John Ericsson, the Monitor had an unusually low profile, rising from the water only 18 inches. The flat iron deck had a 20-foot cylindrical turret rising from the middle of the ship; the turret housed two 11-inch Dahlgren guns. The ship had a draft of less than 11 feet so it could operate in the shallow harbors and rivers of the South. It was commissioned on February 25, 1862, and arrived at Chesapeake Bay just in time to engage the Virginia.

After the famous duel, the Monitor provided gun support on the James River for George B. McClellan’s Peninsular Campaign. By December 1862, it was clear the ship was no longer needed in Virginia, so she was sent to Beaufort, North Carolina, to join a fleet being assembled for an attack on Charleston. The Monitor served well in the sheltered waters of Chesapeake Bay, but the heavy, low-slung ship was a poor craft for the open sea. The U.S.S. Rhode Island towed the ironclad around the rough waters of Cape Hatteras. As the Monitor pitched and swayed in the rough seas, the caulking around the gun turret loosened and water began to leak into the hull. More leaks developed as the journey continued. High seas tossed the craft, causing the ship’s flat armor bottom to slap the water. Each roll opened more seams, and by nightfall on December 30, the Monitor was in dire straits.

That evening, the Monitor’s commander, J.P. Bankhead, signaled the Rhode Island that he wished to abandon ship. The wooden side-wheeler pulled as close as safety allowed to the stricken ironclad, and two lifeboats were lowered to retrieve the crew. Many of the sailors were rescued, but some men were terrified to venture onto the deck in such rough seas. The ironclad’s pumps stopped working, and the ship sank before 16 of its crew members could be rescued. The remains of two of these sailors were discovered by divers during the Monitor’s 2002 reemergence.

READ MORE: When Ironclads Clashed: How Hampton Roads Changed Naval Warfare Forever