sentences:  After Guggenheim's death, members of the Guggenheim family who sat on the foundation's board of directors had personal and philosophical differences with Rebay, and in 1952 she resigned as director of the museum.Nevertheless, she left a portion of her personal collection to the foundation in her will, including works by Kandinsky, Klee, Alexander Calder, Gleizes, Piet Mondrian and Kurt Schwitters.In 1953, the foundation's collecting boundaries extended even further under its new director, James Johnson Sweeney.