Earlier in 1862, a Union Army force commanded by Major General Samuel R. Curtis moved against Little Rock, Arkansas, but became bogged down in the Batesville area due to lack of supplies.

The Union leadership decided to send a naval force from Memphis, Tennessee, up the White River to resupply Curtis's men.

Major General Thomas C. Hindman, the Confederate commander in Arkansas, had fortifications constructed near St. Charles to stop the Union movement.

During the fighting, a Confederate solid shot struck the ironclad USS Mound City, puncturing one of the ship's steam drums.

In what has been referred to as the deadliest shot of the war, scalding steam filled the ship, killing or wounding all but about 25 of the roughly 175 men on the vessel.

The supply mission was unable to make it all the way to Curtis's position, and withdrew back down the river due to low water levels.

The southern state of Arkansas held a statewide election on February 18, 1861, to create a convention to vote on secession, with anti-secessionist delegates initially holding the majority.

During the process, Van Dorn essentially stripped Arkansas of its military strength and supplies, and weakened the Confederate Trans-Mississippi Department.

A separate column commanded by Brigadier General Frederick Steele reached Jacksonport, which was near Batesville and on the White River, on May 4.

[6] The movement caused the Confederate government of Arkansas to retire to Hot Springs,[7] and Curtis's men crossed the White River near Batesville.

[17] On the morning of June 15, the timberclad USS Conestoga, New National, White Cloud, and the steamboat Jacob Musselman left Memphis to join Kilty.

Working to build up the remnants left by Van Dorn's departure, Hindman declared martial law, authorized guerrilla warfare, and formed the base of an army.

With the obstruction incomplete and no other troops available to reinforce the St. Charles position, 35 sailors and naval officers from Pontchartrain, including Lieutenant John W. Dunnington, the vessel's commander, volunteered and were sent down to help man the defenses.

[23] The commander of Maurepas, Captain Joseph Fry, also had his ship, which would have been mismatched against the Union ironclads, scuttled, although a 12-pounder howitzer, a rifled cannon made of brass,[23][24][25] and a third artillery piece were removed first.

[26] The lower battery of 3-inch rifles was strengthened with the brass piece from Maurepas and 34 of Williams's men of the 29th Arkansas Infantry Regiment.

Kilty was unsure of the exact locations of the Confederate batteries, and had the two timberclads hold back while the ironclads moved forward.

The shot hit the ironclad's casemate near a gun port and penetrated the armor, killing three[32] or four sailors outright.

[24] With steam pouring out of her and badly scalded men visible on the decks, Mound City drifted downstream and ran into the riverbank near the lower battery.

[21] With Mound City out of the fight, St. Louis and Dunnington's guns began dueling, until Fitch signaled for the ships to cease fire.

Lexington and St. Louis advanced up to where the sunken ships blocked the river, while Conestoga and Spiteful towed Mound City downstream.

[40] Union soldiers were sent into St. Charles to patrol the town, and the local civilians were warned that it would be razed if guerrilla activity occurred.

Historian Mark Hubbs suggests that seven percent of all Union Navy battle deaths in the entire war were the result of the single catastrophic shot that struck Mound City.

After learning of the fall of St. Charles, the Texans withdrew to DeValls Bluff, where they were reinforced by another regiment, a battalion, and three artillery batteries.

[47] Establishing a supply point at St. Charles,[24] McGunnegle's fleet moved past the river obstructions and continued up the White.

[49] After meeting sporadic Confederate resistance on June 19, the vessels reached Clarendon, Arkansas,[50] where they halted due to low water.

[24][51] At Crooked Point Cutoff, McGunnegle was informed by his pilots that falling river levels would likely strand the ships if they continued further north, so the decision was made to turn around.

After receiving communication from Halleck that he still wanted Curtis reinforced, Grant sent additional supply vessels and transports loaded with the 34th and 43rd Indiana Infantry Regiments to join the White River flotilla on June 26.

Fitch wanted to continue, but learned of a new Confederate strongpoint at DeValls Bluff, and decided that the infantry could not take the position without the gunboats.

On July 7, Brigadier General Albert Rust led Confederate cavalry in an assault on the Union force while it was crossing the Cache River.

Having missed his supply rendezvous, Curtis had his troops leave the White and march to the Mississippi River town of Helena, which was reached on July 12.