U.S.S. Monitor
Designed and built by John Ericsson, the U.S.S. Monitor became the model for an entire class of 60 gunboats, now known generically as "monitors." Her unique
low hull, presenting a small target, was sheathed in 1" iron plate. The rotating gun turret permitted firing in all directions underway.

C.S.S. Virginia (ex-Merrimack)
In July of 1861, the Confederate Navy began converting the partly-burned hull of the captured Union wooden steam frigate Merrimack to an ironclad. Rechristened Virginia, she set forth in March, 1862 to do battle against the blockading U.S. Navy fleet, eventually meeting her match, the Monitor.