Betsey Whitney was the middle daughter of prominent neurosurgeon Dr. Harvey Williams Cushing and Katharine Stone Crowell, who hailed from a socially prominent Cleveland family. Dr. Cushing was descended from Matthew Cushing, an early settler of Hingham, Massachusetts. Dr. Cushing served as professor of surgery at Johns Hopkins, Harvard and Yale Universities, and the family established itself in Boston. Though Betsey had two brothers, she and her two sisters became known in the social world as the “Cushing Sisters”, heralded for their charm and beauty. All three sisters were schooled by their social-climbing mother to pursue husbands of wealth and prominence, and coached to become socially acceptable to important men. As a result of their mother’s coaching to marry well, all three Cushing sisters married into wealth and prominence: Betsey’s older sister, Mary, married Vincent Astor, the heir of a $200 million fortune, in 1940, and her younger sister Barbara “Babe” was married to Standard Oil heir Stanley Mortimer, Jr., and to CBS founder William S. Paley. Both of Betsey’s sisters died of cancer within months of each other in 1978. Betsey Whitney married James Roosevelt II in 1930, the eldest son of President Franklin Delano Roosevelt and First Lady Anna Eleanor Roosevelt. They had two daughters, Sara Delano Roosevelt and Kate Roosevelt. After her father-in-law became President, Betsey was reportedly FDR’s favorite daughter-in-law, though she and Eleanor did not care for one another.

Her husband served his father as an aide at the White House, and Betsey often stood-in as hostess at the White House when Eleanor was absent. When FDR entertained King George VI and Queen Elizabeth at a picnic at the Roosevelt estate in Hyde Park, New York in 1939, Betsey was prominent at the affair, and accompanied FDR as he drove the King and Queen along the Hudson River. In 1938, James left for Hollywood to work as an aide to Samuel Goldwyn. Betsey followed him, but they divorced in 1940. Betsey was granted custody of their daughters, along with child support, though by biographers’ accounts, James had little to no contact with his children, and eventually married three more times. On March 1, 1942, Betsey Whitney married millionaire John Hay Whitney, who had been previously married to socialite Elizabeth Altemus. They moved to London in 1957, when President Dwight D. Eisenhower named Whitney Ambassador to the Court of St. James’s. The family became close to Queen Elizabeth II and Prince Philip, who, in a radical departure from the usual procedure, addressed the Whitneys by their first names. During the 1970s, John Hay Whitney was listed as one of the ten wealthiest men in the world.[citation needed] The residences at their disposal over the years included the Greentree estate on Long Island; Greenwood Plantation in Georgia; a town house and an elegant apartment in Manhattan; a large summer house on Fishers Island, near New London, Connecticut; a 12-room house in Saratoga Springs, which the Whitneys used when they attended horse races there; a golfing cottage in Augusta, Georgia; and a spacious house in Surrey, England, near the Ascot racecourse. In addition, the Whitneys shared a Kentucky horse farm with Whitney’s sister.

Betsey Whitney established the Greentree Foundation in 1983 to assist local community groups. She was a benefactor of North Shore University Hospital in Manhasset, built in the early 1950s on 15 acres (61,000 m2) donated by Whitney. Betsey was also involved with the Museum of Modern Art (MOMA), Yale University and New York Hospital-Cornell Medical Center. Among her many public activities over the years were memberships on the boards of the Whitney Museum of American Art, the John Hay Whitney Foundation and the Association for Homemakers Service. After her husband’s death in 1982, Betsey donated $8 million to the Yale Medical School, then the largest gift in the school’s history. The National Gallery of Art in Washington, D.C. acquired nine important American and French paintings, as well as $2 million for future acquisitions. She herself left $15 million to New York Hospital-Cornell Medical Center in her own will. Betsey also made art auction history in 1990 by putting up for sale, by Sotheby’s, one of Renoir’s most famous paintings, the sun-dappled cafe scene Bal au moulin de la Galette, Montmartre. It brought $78.1 million, then a record auction price for Impressionist art and the second-highest price for any artwork sold at auction. Betsey Whitney died on March 25, 1998 at North Shore University Hospital in Manhasset, New York. Her personal fortune was estimated at $700 million in 1990 according to Forbes magazine. Her estate bequeathed eight major paintings to the National Gallery of Art.