and the Beginning of the Frontier's End (2012)
Sibley created a five man military commission, and all were officers under his command who had seen action against the Dakota in the last month. Never before had a military commission been created after a conflict between Natives and whites; many convictions would depend on the testimony of mixed-bloods and peace-party Dakotas.
Pope wrote Sibley that his goal was to exterminate the Sioux in Minnesota, meaning those under arrest and the Dakota still at large, and that all should be treated as wild beasts.
General-in-Chief Henry Halleck informed Pope that Sibley had been promoted to Brigadier General (of the Volunteers) in the Union Army, and that Sibley should remain in command of his troops in the field. Halleck wanted to deny Pope his goal of building his own system of military patronage under his command in Minnesota. In effect, Halleck's promotion of Sibley (mildly) told Pope to know his place in the chain of command; Pope took more than a week to inform Sibley of the promotion. Sibley was no longer a Minnesotan acting on behalf of Governor Ramsey and the state . . . Sibley now answered to Lincoln.
Little Crow reached Big Stone Lake, which was the area of Chief Standing Buffalo, the most powerful and influential of the Dakotas in the Upper Agency. Standing Buffalo told Little Crow about Sibley's letter offering peace if he captured/detained Little Crow. Standing Buffalo told Little Crow that while he wouldn't detain him or his people, he would not allow Little Crow passage through his territory as they moved west. Standing Buffalo added that he would not join, supply, or support Little Crow in any way. In closing, Standing Buffalo basically scolded Little Crow in front of the gathered Dakotas, and told him to go and leave his land. So, with no other option, Little Crow detoured around Standing Bear's lands, and left the prairies of Minnesota for the Great Plains of the Dakota Territory in order to escape Sibley's pursuit.
At Camp Release, the number of Dakota and mixed-blood prisoners reached over 1200, with about 300 of fighting age. Pope, all the while in St. Paul, sent message-after-message to Sibley, dispatches that were not grounded in any reality. Pope wanted Sibley to scorch the earth so Little Crow wouldn't have any supplies on his return; Pope had convinced himself that Little Crow would return with thousands of warriors to invade Minnesota. It simply didn't register to Pope that most Dakotas were not even remotely a threat, or that Little Crow was currently focused on escape, not invasion. In the field, Sibley had zero plans to send men into the Great Plains in pursuit of Little Crow, regardless of any orders to do so from Pope.
On 6 October 1862, Sibley received a letter from Pope that directed him to offer a $500 reward for Little Crow, and to round up all Dakotas and make them prisoners in the Lower Agency. And, after a trial, those found guilty would be executed in front of the others. Under pressure to produce results based on those orders, Sibley arrested 250 Dakota in the Upper Agency, many of which were part of the peace-party aligned against Little Crow.