Columbia subject headings:
Slavery--United States--Speeches in Congress.
United States--Politics and government--1857-1861.
Harvard subject headings:
Slavery--United States--Speeches in Congress--1861.
United States--Politics and government--1857-1861.
Princeton subject headings:
Secession.
Slavery--United States--Extension to the territories.
Slavery--United States--Speeches, addresses, etc.