In 1950 the school expanded to K-9 and its basketball and baseball started playing in the North Florida Conference.

The sports teams started calling themselves The Demons, short for Demonstration School.

FSUS is sponsored by Florida State University and is a demonstration school for the FSU College of Education, which is used for exploring teaching techniques as well as being an education center where teachers may observe and participate in best teacher practices; and a vehicle for the dissemination of research findings.

FSUS and the FSU College of Education collaborate for research, observations, etc.

[citation needed] The school's mascot were the "Demons", but were renamed after the Florida State Seminoles in 1995.