President Roosevelt signed his name on a bill on December 23rd, 1936, and the land next to the Ocmulgee River, officially became a national park.
Shortly before that bill was signed, archeologists had discovered there was something very unique about these old Indian grounds.
Number one, the giant earth mounds held history that dated back some 17,000 years.
They also found a one-of-a-kind earth lodge unlike any other in the country.
The Macon earth lodge has a floor so well preserved, archeologists could clearly identify its age and size. Something no other earth lodge was previously able to do.
Ocmulgee National Monument Superintendent Jim David says, making these lands a national park, was the best way to preserve it's history.
"We get about 120,000 visitors a year here. They come from all 50 states, and 35 to 40 foreign countries. That is a good economic impact on Bibb County and the city of Macon," David says.
The park crew celebrated the birthday, not with a big bash. Rather, they had cake and punch to mark the occasion.