Hello historians,
What are some interventions before 1920 that improved human well-being 100 years later?
For examples:
- Holden Karnofsky cited United States Hookworm reduction starting around 1909.
https://www.openphilanthropy.org/research/philanthropys-success-stories/
https://en.wikipedia.org/wiki/Hookworm_infection#Eradication_programmes
- Jason Crawford cited Smallpox inoculation before 1700 and vaccination starting around 1796.
https://rootsofprogress.org/smallpox-and-vaccines