March 1862. The Union ironclad warship, Monitor, with its two eleven-inch Dahlgren smoothbores in a unique revolving turret assembly, leaves New York City under tow to serve blockade duty off the coast of North Carolina. Meanwhile, the Confederate ironclad Virginia (formerly the wooden frigate Merrimac) is raising havoc with Union blockaders in Hampton Roads. The inevitable showdown takes place on March 9. For more than four hours the two ironclads battle furiously at close range. The Merrimac finally withdraws and returns to Norfolk to protect the river approaches to Richmond, leaving the Monitor in control of the Roads and in position to protect the Union blockaders. In May, the Merrimac is destroyed by its own crew to prevent capture; in December, the Monitor sinks in a storm off Cape Hatteras while under tow from Hampton Roads to North Carolina waters. An exciting account of two ships that would change naval warfare forever.