The third Boxer was an English-built iron “side-wheeled” steamer and was originally known as the Tristam Shanty. It measured 222 feet in length and 23 feet in width. The Tristam Shanty was used by the Confederate military to run blockades the U.S. had established during the Civil War. She was captured by the USS Kansas May 15, 1864, then purchased by the Navy from the Boston Prize Court and commissioned into service as the USS Boxer Aug. 12, 1864.
For more detailed history on the third USS Boxer visit the Navy Archive page