USS Wachusett (1861) – the first U.S. Navy ship to be so named – was a large (1,032-ton) steam sloop-of-war that served the United States Navy during the American Civil War. She was outfitted as a gunboat and used by the Navy as part of the Union blockade of the Confederate States of America. When the war was over, Wachusett continued to serve the Navy, protecting American interests in both the Atlantic Ocean as well as the Pacific Ocean until she was finally decommissioned.