Franklin Roosevelt was more sympathetic to the Allied cause due to his friendly relationship with Churchill.
During the course of the war, Frankin Roosevelt and Churchill met on numeorus occasions to plan war strategy. The British prime minister visited the United States four times between 1941 and 1944. Some of these encounters were at Frankin’s home in Hyde Park. Furthermore, the most significant of these was held in the study at President Roosevelt’s home on September 14, 1944 where Roosevelt and Churchill initialed a document called the Hyde Park Aide Memoire that outlined the collaboration between the United States and Great Britain in the development of an atomic bomb.