Columbia subject headings:
Slavery--Law and legislation--United States--Cases--Bibliography.
Slavery--United States--Legal status of slaves in free states--Cases--Bibliography.
Harvard subject headings:
Slavery--Law and legislation--United States--Cases--Bibliography.
Slavery--United States--Legal status of slaves in free states--Cases--Bibliography.
Slaves--Legal status, laws, etc.--United States--Cases--Bibliography.
Princeton subject headings:
Slavery--Law and legislation--United States--Cases--Bibliography.
Slavery--United States--Legal status of slaves in free states--Cases--Bibliography.