USS Calhoun was a captured Confederate steamer and blockade runner acquired by the Union Navy from the prize court during the American Civil War.
Calhoun was put into service as a gunboat by the Union Navy to patrol navigable waterways of the Confederacy to prevent the South from trading with other countries.
As CSS Calhoun, she served as flagship for Commodore G. N. Hollins, CSN, during a successful engagement between his fleet and five Union ships at the Head of the Passes into the Mississippi River, 12 October 1861.
Remaining in the Berwick Bay area on patrol, Calhoun and her consorts climaxed their extremely successful operations on April 14, 1863, when they attacked the cotton-clad steamer CSS Queen of the West.
One shot at long range from Calhoun turned the Confederate ship into a torch, and a major threat to Union forces in the area was destroyed.