Columbia subject headings:
Labor laws and legislation--United States.
Land tenure--United States--History.
Slavery--United States.
United States--Economic conditions.
United States--Social conditions.
Harvard subject headings:
Labor laws and legislation--United States
Land tenure--United States--History
Slavery--United States
Social legislation--United States--History.
United States--Economic conditions.
United States--Social conditions--To 1865.
United States--Social conditions.
Princeton subject headings:
Labor laws and legislation--United States.
Land tenure--United States--History.
Slavery--United States.
United States--Economic conditions.
United States--Social conditions.