Columbia subject headings:
Wagner, Richard, 1813-1883--Congresses.
Wagner, Richard, 1813-1883--Influence--Congresses.
Harvard subject headings:
Wagner, Richard, 1813-1883--Congresses.
Wagner, Richard, 1813-1883--Influence--Congresses.
Princeton subject headings:
Wagner, Richard, 1813-1883--Congresses.
Wagner, Richard, 1813-1883--Influence--Congresses.