Two days later, Shawmut got underway to search for Confederate Navy commerce raider, CSS Tallahassee (renamed Olustee), which had recently preyed upon Northern shipping off the Delaware capes.

On the latter day, a boat from Shawmut was destroyed by a torpedo (the Civil War term for a mine) as it swept waters in the area.

With the fall of Richmond and General Robert E. Lee's surrender, Shawmut was ordered north and decommissioned at the New York Navy Yard on 17 April 1865.

Following over a year's service on the Brazil Station protecting "our flag from insult and the property of our citizens from unlawful seizure," Shawmut returned home and was decommissioned at the New York Navy Yard on 8 December 1866.

Recommissioned on 12 August 1867, Shawmut served in the North Atlantic Blockading Squadron until she was laid up again at New York City on 7 July 1868.