Throughout the Civil War, "Supply" supported the blockading squadrons on the United States East Coast and in the Gulf of Mexico. She took her sole prize of the conflict on 29 January 1862. when she captured the schooner "Stephen Hart", which was carrying arms and ammunition, south of Sarasota, Florida. Her services, although undramatic, enabled many warships to remain on station in the blockade and thus helped substantially to shorten the war.