WREG was told the event's single focus would be pediatric cancer.
Patients said seeing complete strangers running for them, to help find them a cure was one of the best feelings they've ever experienced.
"High-fiving all of these racers seeing their faces, and just saying thank you," Adam Cruthirds, the head of Adam's Army said when asked what he would be doing that day.
Last summer, he was diagnosed with leukemia, and ever since has come to St. Jude every-other-day for treatment.
The St. Jude races raise money to go towards research that will put an end to childhood cancer like Cruthirds'.
St. Jude said it would be hosting the 5k in 58 cities across the country during the entire month of September.
Memphis City Mayor A C Wharton said the runners who travel here for the 5k would lead the race.
And the location couldn't be more perfect.
"An institution that has captured the hearts of the nation, the hearts of the world no less, ought to be in the heart of the city," Wharton explained.
And Adam hoped to be one of the major fundraisers.
He told WREG he's already raised $50 thousand for St. Jude but hoped to reach $1 million.