When Gen. Braxton Bragg took the bulk of his army from Tupelo, Mississippi to Chattanooga to launch his offensive into Kentucky in late summer of 1862, he left 2 seperate Confederate forces in Mississippi. Guarding Vicksburg against the Union threat via the Mississippi River was a force of about 16,000 men under Maj. Gen. Earl Van Dorn. Another force of about equal size under Maj. Gen. Streling Price confronted the Federals in northern Mississippi. Bragg left orders for Price to prevent Grant from detaching troops in Mississippi and West Tennessee to reinforce troops in Kentucky. If Grant did detach troops, and perhaps if he did not, Price would press into Middle Tennessee, to join Bragg for the showdown in Kentucky. Once the threat to Vicksburg ended, which it did at this time, Van Dorn was to act on the same orders as Price.
Price and Van Dorn refused to cooperate with each other. Van Dorn outranked Price, but would not be able to give him orders until the 2 forces were actually united, an event that for some time seemed unlikely as each general followed his own agenda. Price thought that they ought to obey Bragg's orders, move northwest, threaten Grantm and see if they could get into Middle Tennessee. Van Dorn had various unrealistic ideas about taking Memphis.
With the 2 Confederate forces still maneuvering seperately, Price advanced toward the town of Iuka, Mississippi. Iuka was a small Union supply depot, the eastern most point on the Memphis & Charleston Railroad held by Grant's troops. A few miles west of the Tennessee River, Iuka was 22 miles east of the main rail junction and Union base at Corinth. Price's advance guard arrived at Iuka on the morning of September 13th. The Union commander, Col. Robert Murphy, put up a half-hearted defense and then promptly withdrew his force toward Corinth, allowing the valuable supplies to fall into Price's hands.
Although he was displeased with Murphy's performance, Grant nevertheless saw an opportunity to destroy Price's small army and marched toward Iuka with 17,000 men. Grant's subordinate, Brig. Gen. William S. Rosecrans, pursuaded Grant to allow him to take 9,000 men from Grant's force and march around the south side of Iuka, so that the Confederates would be caught between 2 converging Union forces. This questionable tactic went astray almost immediately as Rosecrans 's column got bogged down on muddy roads and failed to get into place on time. Grant directed his column not to attack until they heard Rosecrans gunfire.
Then, as Rosecrans's column approached within several miles of Iuka on the evening of the 19th, Price attacked savagely. While Grant's men could not hear Rosecrans gufire, Rosecran's force fought a small but extremely intense battle involving about 4,500 men of his men and 3,200 of Price's men. The fight was inconclusive. Rosecrans, who was supposed to know the area's roads well, had left 1 key route open, and Price's Confederates were able to escape before Grant's troops got word that a fight had taken place.
Having escaped from Grant's trap, Price finally united with Van Dorn, who had adopted a more cooperative attitude by this time. They agreed that their next step should be an attack on Corinth. Their forces arrived near the Union base on October 3rd. Rosecrans defended the town with a force that Grant had by then reinforced to some 23,000 men. Van Dorn, with about 30,000 men, hoped to surprise Rosecrans by marching northwest of Corinth and then turning to attack the town from that direction. However, this strategy accomplished little beyond making Van Dorn's army vunerable to being trapped by Grant's troops, which were closing in rapidly from several directions.
Throughout October 3-4th, Van Dorn hurled his troops at Rosecrans's defenders. Rosecrans unwisely had many of his troops fight outside of their breastworks, and when the Confederate troops briefly broke through his lines and actually reached the streets of Corinth, Rosecrans panicked. Nevertheless, the stubborn fighting quality of his men, along with van Dorn's unimaginative tactics, saved him. After the battle, Rosecrans's failure to pursue saved Van Dorn, who was able to escape the other forces that Grant had sent to trap him.