Map and plan of the fortification.
The Confederate States Army constructed a large, four-sided earthwork fortification near Arkansas Post, on a bluff 25 feet above the north side of the river, forty-five miles downriver from Pine Bluff, to protect the Arkansas River and prevent Union Army passage to Little Rock. The fort commanded a mile view up and downriver. It was a base for disrupting shipping on the Mississippi River. The fort was named Fort Hindman in honor of General Thomas C. Hindman of Arkansas. It was manned by approximately 5,000 men, primarily Texas cavalry, dismounted and redeployed as infantry, and Arkansas infantry, in three brigades under Brig. Gen. Thomas J. Churchill. By the winter of 1862–63, disease and their life at the end of a tenuous supply chain had left the garrison at Fort Hindman in a poor state.
Union Maj. Gen. John A. McClernand was an ambitious politician and had permission from President Abraham Lincoln to launch a corps-sized offensive against Vicksburg from Memphis, Tennessee, hoping for military glory (and subsequent political gain). This plan was at odds with those of Army of the Tennessee commander, Maj. Gen. Ulysses S. Grant. McClernand ordered Grant's subordinate, Maj. Gen. William T. Sherman, to join the troops of his corps with McClernand's, calling the two corps the Army of the Mississippi, approximately 33,000 men. On January 4, he launched a combined army-navy movement on Arkansas Post, rather than Vicksburg, as he had told Lincoln (and did not bother to inform Grant or the general in chief, Maj. Gen. Henry W. Halleck).