Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. USS Agassiz (1861) was borrowed by the Union Navy from the U.S. Coast Survey during the American Civil War. She was used by the Union Navy as a gunboat in support of the Union Navy blockade of Confederate waterways. Soon after the outbreak of the Civil War, the United States Coast Survey ship Agassiz was transferred to the Revenue Cutter Service and took the place of Arago as a receiving ship in New York harbor. On 30 December 1861, she was ordered to Sag Harbor at the end of Long Island, New York, and served as a revenue cutter at that port into the spring of 1862. On 4 June 1862, the vessel was ordered to New London, Connecticut, and arrived at her new base six days later.