Clark graduated from high school in 1916. Due to financial constraints, she was not able to attend college initially, so she took a state examination at the age of eighteen to allow her to teach. As an African American, she was barred from teaching in the Charleston, South Carolina public schools, but was able to find a position teaching in a rural school district, on John's Island, the largest of the Sea Islands. She taught on the islands from 1916 to 1919 at Promise Land School and then returned to Avery from 1919 to 1920. She was able to return to school part-time in Columbia, South Carolina to complete her B.A. at Benedict in 1942 and then she received her M.A. from Hampton. During this time, she taught children during the day and illiterate adults on her own time at night. During this period she developed innovative methods to rapidly teach adults to read and write, based on everyday materials like the Sears catalog.
