Columbia subject headings:
Harvard subject headings:
Canada--Foreign relations--Confederate States of America.
Canada--Foreign relations--United States.
Canada--History--1841-1867.
Canada--Politics and government--1841-1867.
Confederate States of America--Foreign relations--Canada.
United States--Foreign relations--1861-1865.
United States--Foreign relations--Canada.
United States--History--Civil War, 1861-1865
United States--History--Civil War, 1861-1865--Underground movements.
Princeton subject headings:
Canada--Foreign relations--United States.
Canada--History--1841-1867.
United States--Foreign relations--Canada.
United States--History--Civil War, 1861-1865.