Battle of Drewry's Bluff

With the fall of Yorktown, the Confederate ironclad Virginia at Norfolk was scuttled to prevent her capture. This opened the James River to Federal gunboats. On May 15, five gunboats, including the ironclads Monitor and Galena, steamed up the James to test the Richmond defenses. They encountered submerged obstacles and deadly accurate fire from the batteries at Drewry’s Bluff, which inflicted severe damage on the Galena. The Federal Navy was turned back.

http://www.nps.gov/hps/abpp/battles/va012.htm