America's lifespan has doubled since 1776 — experts reveal what changed

Americans today live roughly twice as long, on average, as they did when the Declaration of Independence was signed.

When the nation was founded in 1776, life expectancy was around 35 to 40 years old, historians estimate. However, someone who survived childhood in colonial America often lived into their 60s or even 70s.

Today, the average lifespan is about 79 years old, according to data from the Centers for Disease Control and Prevention.

FILTERED WATER AT SPECIFIC AGES COULD ADD MONTHS TO YOUR LIFESPAN DECADES LATER...