Continuing with The Heart of Everything That Is: The Untold Story of Red Cloud an American Legend By Bob Drury & Tom Clavin.

[.... In the spring of 1825, four years after Red Cloud’s birth,Brigadier General Henry Atkinson led one of the earliest American military expeditions up the Missouri River. Atkinson, a decorated veteran of the War of 1812,departed St. Louis for the Yellowstone and was charged with securing treaties of “perpetual friendship” with as many of the Northern Plains tribes as possible. The 475 rifle-bearing soldiers from the1st and 6th U.S. Infantry Regiments who sailed with him were blunt reminders to the Indians of the consequences of failing to grasp the import of this friendship.

The Sioux, eyeing the gun barrels that lined the deck of Atkinson’s wheel boat, were no fools. When the general reached the Oglala camps in South Dakota they laid out a grand banquet of venison,antelope, and buffalo meat.Atkinson noted their extraordinary good health,and recorded the tribe’s number at nearly 1,500, a fourfold increase from Lewis and Clark’s estimate two decades earlier. This was probably an under count,given that not every member of each Oglala band was present. A population explosion of such magnitude over so brief a period could be credited to a miscount by Lewis and Clark. More likely it indicated the beneficial influence of the horse. Not only had horses allowed the Indians to range farther after game to prevent winter shortfalls and ward off famine and nutritional diseases, but the pack horses had taken on the physical burdens that previously stunted or damaged the ovaries and wombs of women and girls of childbearing age.In addition, being able to act on their bold wanderlust had allowed them to avoid diseases such as smallpox and cholera, which had begun to afflict Indians living in fixed villages across the nation’s massive midsection.

A more subtle purpose of Atkinson’s excursion was to bind the tribes to licensed,regulated trade agreements with the burgeoning United States—as if the words“licensed” and “regulated” had any meaning in Native culture. Nevertheless, gifts were proffered and various Western Sioux Head Men,some actually chiefs, others put forward as a kind of joke on the Americans—touched the pen. For example, on July26, 1825, the Hunk papas “signed” a treaty that began:“For the purpose of perpetuating the friendship which has heretofore existed,as also to remove all future cause of discussion or dissension, as it respects trade and friendship between the United States and their citizens, and the Hunk papas band of the Sioux tribe of Indians, the President of the United States of America, by Atkinson, of the United States Army, and Major Benjamin O’Fallon, Indian agent, with full powers and authority,specially appointed for that purpose, of the one part, and the undersigned Chiefs,Headmen, and Warriors of the said Hunk papas band of Sioux Indians, on behalf of their band, of the other part.” Even the most skilled interpreter could hardly have conveyed the sense of this to the Hunk papas.

The United States may have been in its infancy, but even the Indians of the far West had by now heard stories about a government whose customary double standard ignored nearly all Native interests....]
https://exploringrealhistory.blogspot.com/2019/04/part-3the-heart-of-everything-that.html