"Christian Americans" killed off all of the strongest Native Americans who would fight, and exterminated their food supply
The devastating effects of the 1600's fur wars across the East are well known, Indians eradicating other Indians over access to furs for trade,
In the 1740's the Cherokees, and just the Cherokees, were bringing in more'n 140,000 deerskins a year to the British traders in Savannah. In the 1760's the tribes along the Ohio largely through their Delaware middlemen were bringing nearly 300,000 deerskins a year to the traders at Fort Pitt, eradicating whitetails from large areas and prompting Indian slave raids on each other to acquire the labor to dress all those hides. How them noble savages found the time to apologize to all them deer as PC history tells us they did I dunno.
Buffalo populations went into a steady decline after the Indians got the horse, but most likely what took out more buffalo than anything else was the aforementioned drought across Texas in the 1850's, that and the spread of feral cattle carrying brucellosis and other diseases.
Meanwhile Bent's Fort up on the Arkansas by 1840 was taking in thousands of buffalo hides, all harvested by politically incorrect Plains Indians who left all the surplus meat laying in return for tons of trade goods poled on flatboats up the Arkansas.
Really the eradication of the buffalo didn't change things as much as PC history said it did. As the buffalo dwindled the Comanches and Kiowas sensibly got into livestock herding in a big way in the 1860's such that when Kit Carson went against them in the First Battle of Adobe Walls in November of 1864, all the Indian Camps were surrounded by large herds of cattle. Not often mentioned is the fact that in the first six months of 1873 the Comanches traded 30,000 head of their cattle to the US Army in New Mexico. This early switch to livestock raising is exactly why Quanah Parker was able to slip so seamlessly into the practice when the shooting stopped.
- the less-strong were then left to starve to death. Their only choice was to go to the reservations. Today's Native Americans are the ancestors of the less strong Native Americans, that folks make fun of here on this forum, and use to excuse the genocide that took place.
An idiotic comment but anyways...
In the winter of 1876/77, in the aftermath of the Little Bighorn when all the Lakota who were still out knew the writing was on the wall, General George Crook was able to surprise a camp of Lakota fugitives in the Black Hills. The reason he could do this so easily was that the Indians had been up all night celebrating a scalp dance. Despite their desperate straights the men and youths in the camp had somehow found the time and energy to go out in the dead of winter to massacre a camp of thirty Shoshone men, women and children, and it was the taking of those fresh scalps that they had been celebrating the night before. I often wonder what on earth were those Lakota f&&kheads thinking, their whole universe was falling apart and they take the time to butcher people, other Indians yet..
Plenty Coups of the cleaned up and sanitized account you admire got those plenty coups because he was exceptionally good at killing people. A much better book about the Crows IMHO is "Two Leggings: The Making of a Crow Warrior"
https://www.amazon.com/Two-Leggings-Making-Crow-Warrior/dp/0803283512 ...where Two Leggings hisself graphically details ongoing murders between tribes well after the Frontier Period.