A division of Union troops in the Army of the Frontier, commanded by James G. Blunt, was posted in northwestern Arkansas after winning the Battle of Cane Hill on November 28.

The First Corps, Trans-Mississippi Army, commanded by Thomas C. Hindman moved towards Blunt's division in order to attack while it was isolated.

However, Blunt was reinforced by two divisions commanded by Francis J. Herron, leading Hindman to take a defensive position on some high ground known as Prairie Grove.

The Confederates had to leave many of their dead on the field, in piles and surrounded with makeshift barriers to keep feral pigs from eating the corpses.

[2] After being defeated at Pea Ridge, Van Dorn and a substantial portion of his army were reassigned across the Mississippi River, effectively ending Confederate control of the region.

[3] Following Pea Ridge, Curtis drove further into Arkansas and planned to attack Memphis, but was ordered by Henry Halleck to send half of his force to Cape Girardeau for transfer to Tennessee.

[4] After a defeat in a small action near Searcy, Curtis decided that his supply line was vulnerable, and fell back, eventually reaching Helena.

[8] At the time of Schofield's relinquishment of command, Blunt's division was in Arkansas, while the rest of the Army of the Frontier was stationed near Wilson's Creek in Missouri, where a battle had been fought the year before.

[10][11] On August 21, Holmes tasked Hindman with producing an organized army from the Confederate units in the Arkansas region and moving to regain control of Missouri for the Confederacy.

[26] Blunt's intelligence services alerted him to Hindman's preparations by the evening of December 2; a courier immediately set out for the telegraph station at Elkhorn Tavern.

The messages included a situation report for Curtis in St Louis and an urgent request for Totten to send reinforcements.

[28] Within a few hours of receiving Blunt's telegraphed call for help, on the morning of December 4, Herron started the 2nd and 3rd divisions on "an epic of human endurance".

Herron's two divisions averaged 30 mi (48 km) per day over rough roads in intensely cold weather with short stops to eat and sleep.

Herron promptly dispatched Dudley Wickersham with a 1,600-man provisional cavalry brigade which reached Blunt at 9:00 pm that same day after a 35 mi (56 km) march.

Blunt knew that if Hindman continued to use Cove Creek Road, it would be easy for him to cut off the Confederate retreat route.

[32] On December 6, near mid-day, the 2nd Kansas Cavalry abandoned its blocking position on Cove Creek Road and withdrew northwest toward Newburg.

Helped by the fact that many Confederates wore captured blue uniforms, Shelby's troopers surprised and routed their opponents, especially the 7th Missouri.

[35] The Confederate pursuit continued east past the Illinois River, but ended when it encountered the leading elements of Herron's main column.

[36] During the early morning action, Marmaduke's horsemen inflicted casualties of 10 killed, 19 wounded, and 262 captured on the Union cavalry and seized 21 wagons.

Herron's approaching infantry ignored the panicked Union horsemen and its bold front convinced Marmaduke to pull back to the west side of the river.

[37] By the time Frost's 6,300-strong division reached Prairie Grove, Hindman had lost his nerve and set up a defensive line.

While Hindman waited for Shoup's Arkansas division, Herron had time to push Marmaduke out of his way and reach the Illinois River.

[40] In the early morning, a Union officer detected Hindman's column marching along the Cove Creek Road.

Judson's column got within 0.5 mi (0.8 km) of Prairie Grove and fired its howitzers for 30 minutes, but withdrew when confronted by superior forces.

[43] Later that morning, Herron's Union division reached the field, and, not suspecting that he faced a substantial portion of the Confederate army, opened up an artillery bombardment.

The 26th Indiana attacked Marmaduke's Confederate cavalry, and were driven off by a force that included Shelby's brigade and Quantrill's Raiders.

This attack was also defeated, as the combined fire of Herron's artillery and the survivors of Orme's brigade broke the Confederate assault.

[60] Blunt's forces then prepared to attack the new Confederate left, strengthened by the addition of the 20th Iowa, one of Huston's Union regiments.

In response, Parsons moved his brigade forward from his original position, creating a confused fight between the two armies' main lines.

[1][66] The Confederates were forced to leave many of their dead on the field, and had to pile the bodies into heaps and surround them with makeshift barriers to keep feral pigs from eating the corpses.