Here's a list just to get you started:
Bob Beamon breaking the WR at Mexico City Olympics:
http://blog.adidas-group.com/wp-content/uploads/2012/10/BobBeamon2.jpg
Jesse Owens at the Berlin Oympics:
https://upload.wikimedia.org/wikipedia/commons/c/c5/Jesse_Owens3.jpg
Billy Mills winning the Olympic 10000 meters:
http://images.huffingtonpost.com/2012-09-14-BillyMills5.JPG
Roger Bannister breaking the 4 minute mile:
Tommie Smith and John Carlos doing their black power thing:
http://cdn.bigissue.com/sites/bigissue/files/pa-2373497_tommie_smith.jpg