Artist: William P Hannum (1947 - 1998) Signature: Signed at lower left. Oil or Acrylic On Canvas. Listed Artist: William B. Hannum (1947-1998). "William Hannum was one of the most popular artists in recent times in the California Art Association. His paintings commonly depicted rolling California hillsides, coastal scenes, trees and still life subjects. Bold and broad brush strokes executed with thick, intense color characterized his expressionist style. Hannum created works of art that intentionally conveyed a feeling of robust vitality; through them he expressed his emotional response to nature or an image. His work was highly sought after throughout his fourteen-year association with the CAA until his death from cancer in 1998 at age 51..