USS James Adger was a sidewheel steamer in the Union Navy during the American Civil War. She retained her former name.
Before being pressed into service by the United States Navy, the SS James Adger was a United States Mail Steamship operating between Charleston, South Carolina and New York City, New York. Owned by James Adger II (James Adger & Co) of Charleston, she was seized while in New York City at the outset of the Civil War and converted for military duty by the Union Navy.
James Adger was built at New York City by William H. Webb in 1851. Her 240 hp (180 kW) side-lever engine was supplied by the Allaire Iron Works.
James Adger was purchased at New York for the sum of $85,000 from Spofford, Tileston & Co., on 20 July 1861, and commissioned at New York Navy Yard on 20 September 1861, Commander John B. Marchand in command.