Born Maria Richards Oakey, 27 October 1845, New York City. Probably in 1866, studied at Cooper Union School of Design for Women (New York) with William Rimmer and Robert Swain Gifford. From about 1867–69, studied at National Academy of Design, New York; also met and possibly studied with John La Farge. His flower paintings may have influenced her to specialize in this genre, for prior to 1881 she painted more portraits and figure paintings than still lifes.
May have studied with William Morris Hunt in Boston during early 1870s. 1875, exhibited at Cottier and Company, New York. 1876, first trip to Europe, where she studied with Thomas Couture at Villiers-le-Bel, France; visited Italy and England. 1878, exhibited at the first exhibition of Society of American Artists. Showed regularly at National Academy of Design.
Married Thomas Wilmer Dewing, 18 April 1881; lived in New York. After birth of daughter (1885), painted less frequently, though she collaborated with her husband, completing floral settings for his figures. From 1885 to early 1900s, spent summers in Cornish, N.H., art colony.
1907, one-woman show at Pennsylvania Academy of the Fine Arts. 1914, one-woman show at Knoedler &Co., New York. Died 13 December 1927, New York.
William Kloss Treasures from the National Museum of American Art (Washington, D.C. and London: National Museum of American Art with the Smithsonian Institution Press, 1985)