Williamson lived the first 16 years of her life in West Chester, Pennsylvania, although she was born in Camden, New Jersey on September 15, 1880. Her parents were the noted regional architect T. Roney Williamson and Ada Olympia Clendenin. Her father’s encouragement of her artistic pursuits persisted after his untimely death in 1896, after which she and mother and brother moved to Philadelphia.
In Philadelphia Williamson attended the School of Illustration at Drexel University. She also took courses in the School of Drawing, Painting and Modeling. She completed her training at Drexel in 1900 and began illustration and teaching assignments. In 1902 Williamson enrolled in the Pennsylvania Academy of Fine Art, Philadelphia. With a William Emlen Cresson travel scholarships awarded to her in 1904 and 1905 she studied art in Great Britain and Europe. In the 1920s she was a member of the "Philadelphia Eight", a founding member of the Philadelphia Society of Etchers, and a member of the Philadelphia Print Club. Throughout her career Williamson relied on commissions for illustrations for books and women’s magazines to supplement her income. Her illustrations appeared in Women's Home Companion, Today's Magazine, Harper's, and St. Nicholas. Her real love, however, was portraiture. She painted more than one hundred portraits over a span of forty-eight years.
By 1929 she had moved from Philadelphia to Pasadena, California and was active there through the early 1930s. Williamson spent a good portion of her adult life as a companion to her mother. Mrs. Williamson’s death in 1932 left more time for her to pursue art and art-related interests. She immersed herself in the summer art colony at Ogunquit, Maine, and attended classes in Philadelphia and New York City. She continued to paint until her death in 1958.
Exhibitions and Prizes:
Pennsylvania Academy of the Fine Arts Annuals, 1912, between 1918 and 1924, 1930 and 1946 (prizes in 1922, 1945, and 1948)
Pan-Pacific Expo, San Francisco, 1915
Art Institute of Chicago, 1916, and 1927
Art Club, Carlisle, Pennsylvania, 1925 (solo)
Philadephia Art Alliance, 1927
Philadelphia Society of Etchers traveling exhibition, 1927
Pasadena Art Institue, 1929 (solo)
Painters and Sculptors of Los Angeles, 1929
Woodmere Gallery, 1941
Hughes, Edan Artists in California 1786-1940
Falk, Peter Hastings (Editor) Who Was Who in American Art
Margaret E. G. Robinson and Carolyn D. McCreesh, Ada Clendenin Williamson:Glimpses of the Artist Through Diaries, Letters and Scrapbooks, Chester County Historical Society 1982