The tragic forced relocation of the Navajo.
In the spring of 1864, a US Army detachment herded Navajos from their homes in Northeast Arizona/Northwest New Mexico 400 miles, to the Bosque Redondo near Fort Sumer, NM. Of the approximately 8500 Indians who made the trek, around 200 died of starvation, cold, disease, or other causes. Many more died there due to poor planning, disease, crop infestation and generally poor conditions for agriculture.
In 1868, the federal government basically admitted the plan had failed. The remaining Navajos were allowed to return to their ancestral homes and provided with food and provisions for several years.