At Greenpoint, New York, John Ericsson lays the keel for his revolutionary ironclad

In order to countered the reported conversion of the Confederate's Merrimac into an ironclad, the Navy put out contracts for a ship to match her.  John Ericsson won the contract with a controversial design and, at Greenpoint, New York, the keel had been laid on the Monitor.  The first U.S. Navy vessel to built from scratch as an ironclad, she was built in a remarkable three months and five days and turned over to the navy on February 19, 1861. She was commissioned March 4, 1862 and  famously saw action on March 9, 1862.  (By John Osborne)