In 1944, as the tide of war turned toward the Allies, a weary and ailing Roosevelt managed to win election to a fourth term in the White House . The following February, he met with Churchill and Stalin in the Yalta Conference , where Roosevelt got Stalin’s commitment to enter the war against Japan after Germany’s impending surrender. (The Soviet leader kept that promise, but failed to honor his pledge to establish democratic governments in the eastern European nations then under Soviet control.) The “Big Three” also worked to build foundations for the post-war international peace organization that would become the United Nations.
For years prior to the war, racial prejudice towards Japanese Americans had fueled strong resentment and suspicion among whites living along the West Coast. Feeling pressure from military authorities and the public to protect the homeland from sabotage, Roosevelt felt relocation was the proper action. Though the . Supreme Court upheld its legality in Hirabayashi v. United States and Korematsu v. United States, most legal scholars believe that internment was one of the most flagrant violations of civil liberties in American history. In 1988, Congress awarded restitution to survivors of the camps as compensation for the violation of their civil liberties.
Roosevelt had various extra-marital affairs, including one with Eleanor's social secretary Lucy Mercer , which began soon after she was hired in early 1914.  In September 1918, Eleanor found letters revealing the affair in Roosevelt's luggage. Franklin contemplated divorcing Eleanor, but Sara objected strongly and Lucy would not agree to marry a divorced man with five children.  Franklin and Eleanor remained married, and Roosevelt promised never to see Lucy again. Eleanor never truly forgave him, and their marriage from that point on was more of a political partnership.  Eleanor soon thereafter established a separate house in Hyde Park at Val-Kill , and increasingly devoted herself to various social and political causes independently of her husband. The emotional break in their marriage was so severe that when Roosevelt asked Eleanor in 1942—in light of his failing health—to come back home and live with him again, she refused.  He was not always aware of when she visited the White House and for some time she could not easily reach him on the telephone without his secretary's help; Roosevelt, in turn, did not visit Eleanor's New York City apartment until late 1944.