Richard Diebenkorn’s canvases, drawings, paintings, collages, prints, and a small number of three-dimensional objects, together created over a half century, function as a superbly coherent body of work. His shifts in emphasis from figuration to abstraction to figuration and again back to abstraction take place regardless of...

Norman Wilfred Lewis (1909–1979) was not alone among African American painters of his generation who embraced the contemporary concerns of Abstract Expressionism, often conflating and juggling in their work this commitment to abstraction and figure-based representation. In his “Thesis, 1946” in Norman...