Life expectancy in the 20th centuryLife expectancy increased dramatically in the 20th century.
Life expectancy at birth in the United States in 1901 was 49 years. At the end of the century it was 77 years, an increase of greater than 50%.
Similar gains have been enjoyed throughout the world. Life expectancy in India and The People's Republic of China was around 40 years at midcentury. At century's close it had risen to around 63 years.
These gains were due largely to the eradication and control of numerous infectious diseases and to advances in agricultural technology (such as chemical fertilizers).