President Grant attempts to find a breech made by the Sioux in the 1868 Treaty in order to justify taking the Black Hills away from them. George and Libbie Custer are visited at their home at Fort Abraham Lincoln and the hostiles in the unceded territory are told to report to the reservations by January 31, 1876 or open warfare will be declared on them. In addition, Sitting Bull is introduced, and Custer accuses Belknap and President Grant’s brother of illegal doings which prompts the President to take from Custer the command of the upcoming three-pronged attack on the hostiles.
When President Grant held a high-level Cabinet meeting in 1875, more was decided than to just ignore the miners who entered the Black Hills. In addition, on December 6, 1875, Grant ordered all Indians in the unceded country to move onto the agencies by January 31, 1876. Those Indians who did not comply with this order and were not present on the reservations by that date would be considered hostile. They would be subject to attack, capture, or to be killed by the United States Army.
In other words, it would be open season on all hostile Indians. It was a declaration of war. All that remained to be done, as far as the government was concerned, was to find a breach of faith in the 1868 Treaty. And they found one. Or rather, Indian Inspector E. C. Watkins found one for them. In his report, dated November 9, 1875, Watkins accused the wild Sioux of raiding the Crows in Montana.
If you compare the dates it seems that the government already had their accusation ready when they issued the mandate on December 6, 1875. But in the government’s defense, “The breakdown of negotiations for the Black Hills capped seven years of mounting frustration with the Sioux hunting bands. The hostiles had raided all around the periphery of the unceded territory. They terrorized friendly tribes. They disrupted the management of the reservation Indians while obtaining recruits, supplies, and munitions at the agencies for these hostile activities. And now they interfered with the sale of the Black Hills. The right to roam outside the boundaries of the Great Sioux Reservation—in the unceded territory—made all this possible.” The government had to do something. The people who had elected it demanded that something be done.
General Phil Sheridan
However, in spite of Sioux treaty rights to winter where they liked, if they did not come into the reservation by the given date, “the government would have a pretext not only for punishing the hostiles but for seizing the Hills, either in the course of the fighting or as part of a new peace settlement.”
The case of the matter was that, even if the hostile bands had wanted to come in, which they didn’t, they couldn’t have come, at least by January. It was the dead of winter. If they had tried to come in ‘dead’ is what most of them would have been—frozen and/or starved, and probably on foot since their ponies were in no shape to travel. The Indian ponies would not be up to the job until later in spring when the prairie grasses were abundant and the horses had put on weight and stamina. Granted, the eastern white officials did not have a feel for life on the Plains, but Grant did, Sherman did, and so did Crook and Sheridan. They all knew they were asking, no, demanding an impossibility.