On this day in 1863, the Union army inflicts a heavy defeat on the Confederacy, when they capture Arkansas Post. General John McClernand and Admiral David Porter captured Arkansas Post, a Confederate stronghold on a loop on the Arkansas River. The success virtually secured control of all central Arkansas for the Union and ensured that much of the Mississippi and the Arkansas River remained open to Union ships and trade. Arkansas Post was a heavily fortified fort that overlooked the confluence of the Arkansas and Mississippi River. The Confederates were desperate to retain control of the key fort to deny the Union forces full control of these vital waterways. It was also important as the fortification was able to keep the pressure off Vicksburg, the last major Confederate bastion on the Mississippi.
McClernand gathered his Army of the Mississippi due north of Vicksburg. He divided his forces into two corps of 16,000 men each. The main objective of the Army of the Mississippi was Vicksburg but Arkansas Post was deemed strategically important in order to ensure Union control of the Arkansas River. The Union army that advanced on Arkansas Post was accompanied by a small flotilla of ships, commanded by Admiral Porter. The flotilla was to land one of the corps just before Arkansas Post and Sherman was to attack from the rear. The attack began when Porter’s ships began to shell the fortification, with their heavy guns. The Confederate garrison was soon surrounded and they had no prospect of receiving any aid or the arrival of a relief force. The Union ships pounded the Confederate garrison for several hours. The Rebels fired at the ships but their fire was largely ineffective. The two corps attacked the walls of the fort almost simultaneously. The Confederates responded to these with intense small arms fire. However, the Confederates knew that they were in an impossible position and they had no chance of success. After an intense day of battle the Confederate commander showed the white flag and the Union army entered Arkansas Post unopposed. The Union lost about 100 men and approximately 1000 wounded. The Confederates did not suffer heavy casualties but the entire garrison surrendered. The victory was received with delight in Washington, as the North had suffered a heavy defeat at Fredericksburg only a few weeks earlier. They had not expected to achieve the capture of such an important fortification of major strategic significance so quickly.