USS Fearnot was purchased by the Union Navy for service during the American Civil War.

She was assigned to blockade duty for which she was prepared with her powerful rifled guns.

Fearnot was built by George W. Jackman Jr., Newburyport, Massachusetts; purchased by the Union Navy 20 July 1861; and commissioned 28 August 1861, Acting Master E. H. Faucon in command.

Her last service, from October 1865 to May 1866, was in carrying surplus ordnance to Pensacola, Florida, and guarding the large amounts of ammunition accumulating there.

This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.