He was the first man to run the 100m in under 10 seconds; he broke the record in 1968 when he recorded a hand-timed 9.9 seconds at the US Championships. He then broke his own record while winning the gold at the 1968 Olympics, where an electronic timer recorded him at 9.95. His record stood for nearly 15 years until Calvin Smith ran a time of 9.93 in 1983. That is the greatest length of time an athlete has held the record for the men's 100m since the International Amateur Athletic Foundation began keeping track in 1913.