Whitney, widow of John Hay ``Jock'' Whitney and the first wife of President Franklin Roosevelt's son, James, has died. Whitney, 89, died Wednesday on Long Island. A philanthropist, Whitney was the second-born of the three Cushing sisters, renowned in the 1930s and '40s for marriages into some of the nation's most prominent families. She inherited the bulk of one of the great American fortunes when Jock Whitney - financier, publisher of The New York Herald Tribune and ambassador - died in 1982. In 1990, Forbes estimated her wealth at $700 million. Whitney established the Greentree Foundation in 1983 to assist community groups. She was a benefactor of North Shore University Hospital where she died, and was involved with the Museum of Modern Art, Yale University and New York Hospital-Cornell Medical Center.