Biographies of American Seedsmen and Nurserymen Vincent, Richard, Jr.–1906–White Marsh, Maryland–located in White Marsh in 1868 and built his first greenhouse in 1870.  He specialized in vegetables and dahlias, chrysanthemums and geraniums.  His company was R. Vincent, Jr. & Sons, his three sons, Richard A., Thomas A., and John S., were associated with him.
Sources:  FlorEx-Sep. 22, 1906