Columbia subject headings:
African Americans--Employment.
Industries--United States.
United States--Emigration and immigration.
United States--Race relations.
Working class--United States.
Harvard subject headings:
African Americans--Employment
Industries--United States
Labor--United States
United States--Emigration and immigration.
United States--Race relations
Working class--United States
Princeton subject headings:
African Americans--Employment.
Foreign workers--United States.
Industries--United States.
United States--Emigration and immigration.
United States--Race relations.