The first Passaic was a single turreted, coastal monitor purchased by the United States Navy for service during the American Civil War.

Passaic, first of a ten-ship class of 1335-ton ironclad monitors, was built by Continental Iron Works, Greenpoint, Brooklyn, New York, under subcontract from John Ericsson.

Two days later the new monitor departed New York and joined the North Atlantic Blockading Squadron at Hampton Roads on 29 November but was immediately sent to the Washington Navy Yard for repairs.

On 7 April, she took part in Rear Admiral Samuel F. Du Pont's attack on Charleston, South Carolina.

From 1878 to 1882 she served as receiving ship at Washington, D.C. From 1883 to 1892 she was stationed at the Naval Academy, Annapolis, Maryland, and from 1893 to 1894 at the Navy Yard, Boston, Massachusetts.