When was the political leader to which Einstein–Szilárd letter was written born? 
Einstein–Szilárd letter: The Einstein–Szilárd letter written by Leó Szilárd and signed by Albert Einstein that was sent to the United States President Franklin D. Roosevelt on August 2, 1939. Franklin D. Roosevelt: Franklin Delano Roosevelt ( , his own pronunciation, or ; January 30, 1882 – April 12, 1945), commonly known as FDR, was an American statesman and political leader who served as the 32nd President of the United States from 1933 until his death in 1945.
January 30, 1882