<P> The first hundred days of a first - term presidency of a President of the United States are sometimes used to measure the successes and accomplishments of a president during the time that the president's power and influence are at their greatest . The term was coined in a July 24, 1933, radio address by U.S. President Franklin D. Roosevelt, although he was referring to the 100 - day session of the 73rd United States Congress between March 9 and June 17, rather than the first 100 days of his administration . </P>

Who started the first 100 days of presidency