Columbia subject headings:
African Americans--Civil rights--History--Sources.
Communism--United States.
National Negro Congress (U.S.)--History--Sources.
Subversive activities--United States--History--20th century.
United States. Federal Bureau of Investigation.
Harvard subject headings:
Princeton subject headings:
African Americans--Civil rights--United States--History--Sources.
Communism--United States.
National Negro Congress (U.S.)--History--Sources.
United States. Federal Bureau of Investigation--Archives.