Brig. Gen. John S. Marmaduke was convinced him that a Confederate show of strength in Missouri would rally its long-suffering Southern sympathizers. In March, he approached Brig. Gen. ?? Holmes with a plan for a large raid. Holmes feared that Missouri Confederates would be hesitant to support Marmaduke unless they were given some indication of a permanent Confederate presence. He was persuaded by arguments that the raid would not only replenish Confederate supplies, but might also relieve the Union threat on Arkansas and persuade Maj. Gen. Ulysses S. Grant to dispatch some troops from his Vicksburg Campaign to protect Missouri. Marmaduke gathered his forces at the Eleven Point River north of Batesville.
On April 17 , Marmaduke led over 5,000 men across the border into southeast Missouri. Almost 1,200 of his men had no weapons and 900 had no horses, but Marmaduke took them anyway because he feared they would desert if he left them behind. He hoped to equip them with captured Union supplies.
The plan was to strike the Union army, under Brig. Gen. John McNeil, at Bloomfield. The Confederates hated McNeil for his brutalities against Confederate sympathizers in Missouri, so the chance to capture or kill him gave the Confederates added incentive. Initially, the operation went well as the Confederates scattered several small Union units and forced McNeil out of Bloomfield. But swollen streams and bad roads, that impeded the march, prevented the Confederates from catching up with McNeil, who was able to reach the safety of the fortified Union supply base at Cape Girardeau on the Mississippi River.
Unwilling to risk his command in an all-out assault on the fortifications at Cape Girardeau, and with his expedition plagued by bad weather and lack of forage for his horses, Marmaduke found his position becoming increasingly tenuous. McNeil was being reinforced by water, and a second Union force, under Brig. Gen. William Vandever, was moving toward him from the west. As Marmaduke began to withdraw south toward Arkansas, some 75 miles away, the two Union armies, whose combined strength he estimated at 8,000 men, united to pursue him.
Marmaduke recorded that his retreat was "orderly and slow. His line of retreat was along the military road that ran atop Crowley's Ridge, an elevated strip of land extending south from Cape Girardeau to Helena, Arkansas. Bounded on both sides by marshy lowlands, the road was the only practical route through the region during the rainy spring season. All travelers on the road between Missouri and Arkansas had to cross the St. Francis River at Chalk Bluff. Marmaduke knew that he would have to construct a bridge across the rain-swollen stream if he was to get his command safely back to Arkansas, and there, at the crossing, he would be most vulnerable.
While his rear guard, made up of Col. J.O. Shelby's Missouri cavalry and Col. George Carter's Texas cavalry, skirmished continuously with advance elements of the Union force, Marmaduke sent a construction party ahead to build a bridge across the St. Francis.
On May 1 , the Confederates reached Four Mile, so named for its location 4 miles from the ferry crossing. Marmaduke began the construction of a series of trenches at intervals from Four Mile to the river. He hoped to fight a delaying action long enough to get his troops across the river into Arkansas. Near sundown, the advancing Federals struck the Confederate position at Four Mile but were repulsed by Confederate artillery.
In the meantime, the bridge detail had been hard at work. From Chalk Bluff, the step-rising ground extended about a mile and a half west. The construction of the bridge was under the supervision of the Missouri raider Jeff Thompson, the " swamp fox of the Confederacy ." He had been an engineer before the war and, upon hearing of Marmaduke's plight, had volunteered his services. Under Thompson's direction, the Confederates took logs from area barns to construct a large raft. Using grapevines and ropes as guy wires, they created a crude floating bridge.
After nightfall, Marmaduke quietly fell back to the trenches nearest the river, and his men began the dangerous task of crossing the bridge in the dark. The structure could not accommodate heavy loads, so the men were forced to cross in single file. A separate raft was constructed to ferry the artillery across. When these guns arrived on the Arkansas side, they were put in place on the heights of Chalk Bluff where they commanded the approaches to the river on the Missouri side. The horses were too heavy for the bridge and were forced to swim the fast-moving stream. Many of the exhausted animals did not make it. The Confederates continued crossing all through the night, the rear guard crossing near dawn on May 2. When the last Confederate had crossed, the supports were cut, and the bridge broke in two and floated downstream.
Union troops were now swarming over the high ground leading down to the river, their pickets moving down to the river bank. Vandever's artillery opened up on the Confederates still in the river bottom, and some of the Confederates returned the fire from atop Chalk Bluff. Another volley from the Union artillery sent the Confederates scurrying behind the crest of the bluff. Artillery and small-arms fire continued for several hours. McNeil showed no inclination to follow the Confederates back into Arkansas. The Confederates withdrew toward Jacksonport.
On May 6 , they entered swampy land along the Cache River, where they battled rain, mud, and mosquitoes for three days.
Accurate casualty figures for the battle at Chalk Bluff are unavailable. The official Union casualty report of all forces operating against Marmaduke between April 17 and May 2 listed 23 killed, 44 wounded, and 53 captured for a total of 120. Marmaduke contended that the number was much higher. He put his own losses at 30 killed, 60 wounded, and 120 missing. He picked up 150 recruits during the course of the raid.
The Battle of Chalk Bluff saved Marmaduke's army and prevented an unsuccessful raid from turning into a total disaster. But neither the Fayetteville attack nor the Cape Girardeau raid had succeeded in reversing the Rebels' sagging fortunes in Arkansas. As spring gave way to summer, their position became increasingly desperate. If the Confederacy in Arkansas were to survive, it would require more than bold, ambitious failures - it would require decisive victories, and soon.