Grayson was a teacher in
Allendale, South Carolina. In 1939, she was forbidden to teach Black history lessons to her students. Later, she succeeded in getting thirteen books on Black history added to the state's approved list for school use.
Carter G. Woodson hired her as field representative at the Association for the Study of Negro Life and History in 1942. Her work included traveling through the eastern United States, holding workshops on teaching Black history, advising on historical preservation, and recommending reading and curriculum materials. She was also secretary of the
Bethune-Cookman College Fund, She was a member of
Alpha Kappa Alpha. After she moved to Los Angeles around 1960, she opened her extensive collections as the Center for Extended American History, in her home on
Crenshaw Boulevard, to support educators and researchers interested in Black history. In her last years, she taught weekly Black history courses at the
men's prison in Chino. ==Personal life==