With its swift current and deep channel allowing deeper-draft vessels to travel reliably as far north as Batesville, the White River was the most important river in Civil War Arkansas and was used extensively by both sides. After the Confederate fleet was defeated at Memphis on the Mississippi River on June 6, 1862, the Confederate gunboats Pontchartrain and Maurepas moved up the White, and the Maurepas was later scuttled at St. Charles, where its remains stay in the river. On June 13, 1862, a Union fleet left Memphis to bring supplies to Maj. Gen. Samuel R. Curtis’s Army of the Southwest by way of the White River, but on June 17 it met Confederate batteries at St. Charles, where a Rebel shell pierced the steam drum of the U.S.S. Mound City and scalded dozens of sailors to death; called the single deadliest shot of the Civil War, that shell caused 7 percent of the total fatal casualties suffered by the Union navy during the war, and falling water levels then forced the flotilla to turn back before reaching Curtis. A Union fleet later used the White River Cutoff to enter the Arkansas River and crush the Confederate base at Arkansas Post on January 9-11, 1863. On January 12, a joint Army-Navy expedition then went up the White in pursuit of Confederate steamboats, captured and partially burned St. Charles, destroyed Confederate supplies at DeValls Bluff, and captured and paroled 39 sick Confederates at Des Arc before returning downriver on the 19th. A Union flotilla met Maj. Gen. Frederick Steele’s army at Clarendon on August 9, 1863, during Steele’s drive to capture Little Rock; part of the fleet then went up the White on August 12 to burn a warehouse full of Confederate supplies at Des Arc and briefly occupy Augusta, while the rest moved up the Little Red River to capture two steamboats. From the fall of 1863 until the end of the war, the Union navy patrolled the White River from a base at DeValls Bluff and often carried out cat-and-mouse operations against Confederate troops and guerrillas in the area. Confederate General J.O. Shelby operated along the White through the summer of 1864, and on June 24, 1864, his cavalrymen slipped into Clarendon, attacked and captured the U.S.S. Queen City while it lay at anchor, seized supplies and weapons, and then sank the vessel; a punitive expedition steamed down the White the next day, but Shelby escaped. On August 30, 1864, Union gunboats escorted infantry up the White in pursuit of Shelby’s Confederates, advancing as far as Augusta under frequent sniping from the banks before returning to DeValls Bluff on September 6.