General Phil Sheridan... had urged the destruction of the bison herds, correctly predicting that when they disappeared the Indians would disappear along with them; by 1885 the bison were virtually extinct, and the Indians were starving to death on the plains.... the Indian Wars finally ended; and with the enforced peace came an economic recession in the West, for the United States government had spent there about one million dollars for every Indian killed by 1870.

Man's Rise to Civilization (1968)