Harry Truman had been America's vice president for just a few months when FDR died, unexpectedly, on the 12th of April, 1945. A man Americans barely knew was now in charge of ending the war and leading the country.
When Truman sought the presidency, in his own right, he was not at all sure he could win. When he did, he gave this inaugural address on the 20th of January, 1949.
President Harry S. Truman - Inaugural Address, 20 January 1949.
Video online, courtesy C-SPAN.