The first USS Mingo, a stern-wheel steamer built at California, Pennsylvania, in 1859 and used to tow coal barges, was purchased at Pittsburgh by Colonel Charles Ellet Jr. in April 1862 for usage in the U.S. Ram Fleet during the American Civil War.

On 10 May the Confederate flotilla made a spirited attack on Union gunboats and mortar schooners at Plum Point Bend, Tennessee, sinking Cincinnati and forcing the Mound City aground.

As the ram fleet and Western Flotilla prepared to attack, General Halleck's capture of Corinth, Mississippi, on 30 May cut the railway lines which supported the Confederate positions at Forts Pillow and Randolph, forcing the South to abandon these river strongholds.

At this point Colonel Ellet ordered his rams to steam through the line of Flag Officer Davis' slower ironclads and to run down the Confederate steamers.

Memphis surrendered to Flag Officer Davis, and the pressure of relentless naval power placed another important segment of the Mississippi firmly under Union control, an open wound in the Confederate heartland.

At the first sight of Arkansas, Lancaster tried to ram the southern ship; but when she was a mere 100 yards from her quarry, a broadside from the ironclad opened up her lines and made her unmanageable.