In a 2025 article published in Proceedings of the National Academy of Sciences, C. Matthew Snipp and colleagues investigate the health consequences of the U.S. Dawes Act of 1887, which sought to assimilate American Indians by distributing reservation lands as individual plots and granting citizenship. Although intended to promote self‑sufficiency, the policy instead resulted in immense land loss and cultural disruption. By the time of its 1934 repeal, American Indians had forfeited approximately two‑thirds of their original reservation lands (~86 million acres), and nearly two‑thirds were landless or faced subsistence struggles.

Using 1900 and 1910 U.S. Census data, the researchers exploit variations in allotment timing across households and tribes to measure mortality effects. They find that child mortality among American Indians increased by just over 15% as a result of the policy. Using different methods, they show that total mortality among younger American Indians may have risen by as much as one‑third, implying a roughly 20% drop in life expectancy at birth—a decline comparable to the mortality shocks seen in World War I France or the 1918 influenza pandemic in the U.S.

The findings substantiate long-standing concerns that the Dawes Act inflicted severe demographic harm in addition to economic and cultural damage.