Carl Lewis was apparently a drug cheat but he got away with it. The drug tests were not as accurate back then and he managed to get away with doping.
All of the 8 competitors of the 1988 Seoul Olympic 100m Final had at one time been found guilty of doping. That was the same event Ben Johnson was stripped of his Olympic gold medal for steroids. Carl Lewis was awarded the gold medal. How ironic the American sprinter never got caught and won 9 Olympic gold medals over his career.
However in recent years American sprinters both men and women have been caught and banned due to the improved drug tests.