At Greenpoint, New York, John Ericsson's new ironclad is completed and turned over the the U.S. Navy.

To counter the reported conversion of the Confederate's Merrimac into an ironclad, the Navy had put out contracts for a ship to match her.  John Ericsson won the assignment with a controversial design and on October 28, 1861, at Greenpoint, New York, the keel had been laid on the Monitor.  The first sea-going U.S. Navy vessel designed from scratch as an ironclad, she was built in a remarkable three months and five days and turned over to the navy on this day. She was commissioned March 4, 1862 and  famously saw action on March 9, 1862.  (By John Osborne) 
Source Citation
Bruce Linder, Tidewater's Navy: an illustrated history (Annapolis, MD: U.S. Navy Institute Press, 2005), 72. 
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