Columbia subject headings:
Agricultural ecology--United States--History--19th century.
Agricultural ecology--Virginia--History--19th century.
Ruffin, Edmund, 1794-1865.
Secession.
Slavery--Southern States--History--19th century.
Southern States--Politics and government--1775-1865.
Statesmen--Virginia--Biography.
Harvard subject headings:
Agricultural ecology--United States--History--19th century.
Agricultural ecology--Virginia--History--19th century.
Ruffin, Edmund, 1794-1865.
Secession--Southern States.
Secession.
Slavery--Southern States--History--19th century
Southern States--Politics and government--1775-1865.
Statesmen--Virginia--Biography.
Princeton subject headings:
Agricultural ecology--United States--History--19th century.
Agricultural ecology--Virginia--History--19th century.
Ruffin, Edmund, 1794-1865.
Secession.
Slavery--Southern States--History--19th century.
Southern States--Politics and government--1775-1865.
Statesmen--Virginia--Biography.