Columbia subject headings:
Harvard subject headings:
Rome--Antiquities--Congresses.
Slavery (Roman law)--Congresses.
Slavery--Rome--History--Congresses.
Princeton subject headings:
Canon law--Congresses.
International law--Congresses.
Roman law--Congresses.
Slavery--History--Congresses.
Slavery--Law and legislation--History--Congresses.
Slavery--Rome--Congresses.
Slavery--United States--History--Congresses.