On January 11, 1863, Union General John McClernand and Admiral David Porter capture Arkansas Post, a Confederate stronghold on the Arkansas River. The victory secured central Arkansas for the Union and lifted Northern morale just three weeks after the disastrous Battle of Fredericksburg, Virginia.
Arkansas Post was a massive fort 25 miles from the confluence of the Arkansas and Mississippi rivers. It was designed to insure Confederate control of the White and Arkansas rivers, and to keep pressure off Vicksburg, Mississippi, the last major Rebel city on the Mississippi River. The sides of the square fort were each nearly 200 feet long and the structure was protected by a moat. It sat on a bluff 25 feet above the river. The post was a major impediment to Yankee commerce on the Arkansas.
McClernand gathered his Army of the Mississippi at Milliken’s Bend, just north of Vicksburg. He had some 32,000 men in two corps commanded by generals George Morgan and William T. Sherman. McClernand’s main objective was Vicksburg, but he decided to capture Arkansas Post first to secure Yankee commerce on the rivers north of Vicksburg. McClernand was accompanied by Porter’s flotilla. The plan was to steam up the Arkansas River and land the troops below the post, then have Sherman’s men swing around behind the fort while Morgan approached from downriver.
Porter began bombing the fort on the night of January 10. The bombardment continued the following day. Through the afternoon, Union infantry moved toward the fort while the ships passed in front and began firing from the other side of the fort. The Confederate garrison was surrounded, and offered a white flag before the day was out. The Yankees lost around 130 men and suffered about 900 wounded, but they captured 5,000 Confederates and preserved Union commerce on the Arkansas and White rivers.