Franklin Delano Roosevelt: First Inaugural Address
On March 4th, 1933, Franklin D. Roosevelt delivered his first inaugural address, which is considered one of the most important speech of the 20th century (rank 3 in the Top 100 in the list compiled by Professors Stephen E. Lucas and Martin J. Medhurst).
You can find a better quality audio version as well as a transcript at AmericanRhetoric.com.