USS Yazoo — a single-turreted, twin-screw monitor — was laid down in March 1863, before final government approval had been given, by Merrick & Sons, Philadelphia.; launched on 8 May 1865; and completed on 15 December 1865. Yazoo was a Casco-class monitor intended for service in the shallow bays, sounds, rivers, and inlets of the Confederacy. These warships sacrificed armor plate for a shallow draft and were fitted with a ballast compartment designed to enable them to ride exceptionally low in the water during battle.