Columbia subject headings:
Higginson, Thomas Wentworth, 1823-1911.
Kansas--History--1854-1861.
Massachusetts Emigrant Aid Company.
Slavery--Kansas.
Harvard subject headings:
Higginson, Thomas Wentworth, 1823-1911.
Kansas--History--1854-1861.
Massachusetts Emigrant Aid Company.
Slavery--Kansas.
Princeton subject headings:
Higginson, Thomas Wentworth, 1823-1911.
Kansas--History--1854-1861.
Slavery--United States--History.