Sanitation and hygiene, dental care, antibiotics, and vaccines. In some cases, improved diet. Those are, I believe, the biggest factors in increasing life exp

Sanitation and hygiene, dental care, antibiotics, and vaccines. In some cases, improved diet. Those are, I believe, the biggest factors in increasing life expectancies. Perhaps also pregnancy and infant care, getting 0 to 5 year olds past historically high death rates. And, sadly, an area (not the only one) where the U.S. has regressed significantly.