Poorly rationed and hampered by muddy conditions, the soldiers eventually had to butcher and eat their horses and mules as they became lame or injured.
The Horsemeat March ended with the Battle of Slim Buttes and the capture and looting of American Horse the Elder's richly stocked village.
The intention of the Army's senior commanders was to reunite their soldiers with Custer's in order to finally win the battle by overwhelming the native camps.
On June 24, Custer's troops found shelter on an overlook called Crow's Nest, about fourteen miles east of the Little Bighorn River; from here they spotted a herd of ponies.
The gathering had been called together by Hunkpapa Lakota religious leader Sitting Bull and consisted of approximately 1800 men, including such notable warriors as Crazy Horse and Gall.
Under the leadership of Crazy Horse, the native warriors decimated Custer's soldiers, forcing a small remnant of his command to defend themselves at a spot now known as Last Stand Hill.
Following the battle, the United States increased the size of its army and began a campaign to chase the large force of native warriors that had succeeded against Custer.
General George Crook, who commanded over one thousand cavalry and infantry soldiers together with numerous Native American scouts, eventually took the helm of a punitive military campaign against the Sioux.
In December 1876, Dr. Clements filed a report on General Crook's campaign against the Sioux, detailing the Horsemeat March and the Battle of Slim Buttes.
One entry, on August 31, 1876, illustrates the intense difficulties encountered by Crook's troops: Long marches in the most frequent of rain-storms, with cold nights and heavy dews, and the prospect of achieving satisfactory results, always so encouraging to the soldier, was not apparent.
Clements' report describes an exhausting trek through the badlands of the Dakota Territory, which became lakes of mud in the stormy weather that accompanied the journey.
On the way there, the troops discovered the Lakota tribe, in particular, an encampment of Oglala men, women, and children near Slim Buttes, in present-day South Dakota.
At dawn on September 9, roughly 150 men led by Captain Anson Mills attacked the Oglala encampment, though the Natives fought back fiercely.