Roosevelt’s health was in decline as FDR prepared in 1944 for both a fourth run at the presidency and the aftermath of World War II. A March 1944 examination by his doctors revealed a variety of heart ailments, high blood pressure, and bronchitis. Those close to the President—and even those who saw him speak in public—noted his haggard and weak appearance, his flagging energy, and his increasing lapses of concentration and memory. Most of the American public was unaware of the President's struggles—though rumors about FDR's health often ran wild—and FDR delivered a few key, command performances in 1944 that quieted concerns. Nonetheless, Roosevelt's election victory over Thomas E. Dewey in 1944, in addition to the Yalta Conference the following February, put the President under immense strain. In April 1945, FDR returned to Warm Springs, Georgia, a destination that had served since the 1920s as his favorite retreat. There, on April 12, while sitting for a portrait, he collapsed and died of a cerebral hemorrhage. Vice President Harry Truman took the oath of office the same day.

Roosevelt's passing stunned the world. Churchill later described learning of FDR's death as comparable to having "been struck a physical blow." Stalin, too, was distressed to learn of FDR's passing. Many Americans no doubt agreed with these leaders. Hundreds of thousands of people, many with tears in their eyes, lined the train route carrying his body from Georgia to Washington, D.C., and then on to Hyde Park, to pay their final respects. Roosevelt was buried in Hyde Park, New York, on April 15, 1945.