After elementary school, Claude Black attended Frederick Douglass School, a segregated school in San Antonio located on Rincon St. (hence the school's alternate name, Rincon School) until 11th grade. The school did not offer 12th grade. The class of 1932-1933 was the last class to graduate from Frederick Douglass School before it moved locations and became the Wheatley School. The original Rincon campus later became Frederick Douglass Elementary School.
Claude Black remained involved in the legacy of his high school, attending the 50th anniversary reunion in 1983 with his wife ZerNona and working with the San Antonio Conservation Society to create a historical marker for the historic campus of the Rincon/Douglass School in the 1990s.
During the three-day long 50th graduation anniversary reunion, Rev. Black posed for a photograph with the other members of the class of '33 on the steps of the historic campus, now Frederick Douglass Elementary. He and ZerNona also partook in other events at the reunion.