Harpending's plan to capture
Pacific Mail Steamship Company ships along the Pacific coast carrying gold and silver shipments to
Panama. He intended to then take what he seized to support the Confederacy. The plan attempt was detected and a boarding party made up of crew from the
United States Navysloop-of-warUSS Cyane, revenue officers, and
San Francisco Police Department officers seized the ship and its crew on the night of their intended departure.[2][3]