In the spring of 1864, Lt. Gen. Richard Taylor, directly under Smith's command, soundly defeated Maj. Gen. Nathaniel P. Banks at the Battle of Mansfield in the Red River Campaign on April 8, 1864. After the Battle of Pleasant Hill on April 9, Smith joined Taylor and dispatched half of Taylor's army, Walker's Greyhounds, under the command of Maj. Gen. John George Walker, northward to defeat Union Maj. Gen. Frederick Steele's incursion into Arkansas. This decision, strongly opposed by Taylor, caused great enmity between the two men.