USS Marion was a sloop-of-war of the third rate in the Union Navy during the American Civil War launched at the Boston Navy Yard on 24 April 1839. On 10 November 1839, she departed Boston on her first cruise, to Brazil. Sunk when heaved down in the harbor at Rio de Janeiro early in 1842, she was raised and sailed back to Boston, arriving in May. She then set sail for the Caribbean, returning in May 1843. For the next few years, she remained in ordinary at Boston and then cruised off the West Coast of Africa and in the Mediterranean until 1848. After a tour in the East Indies from 1850–52, she resumed operations with the African Squadron from 1853–55 and 1858-60. 1856-57 was spent in ordinary at Norfolk.