Major changes in the 20th century that contributed to a longer lifespan
The average life expectancy in the United States lengthened by more than 30 years during the 20th century alone, a monumental demographic shift. This remarkable improvement in longevity was driven by a combination of profound scientific breakthroughs, transformative public health initiatives, and widespread socioeconomic improvements that represent the major changes in the 20th century that has contributed to a longer lifespan.