He almost retired , but decided the London Games would be his sendoff from the sport he began as a wispy child in Baltimore . Michael Phelps swam one event in his first Olympics , placed fifth . At age 15 , though , people saw his potential to be great swimmer . Four Olympics later he has the most medals of all time , most gold . He increased the popularity of the sport in America through record - setting performances .
Michael Phelps swam one event in his first Olympics , placed fifth . At age 15 , though , people saw his potential to be great swimmer . Four Olympics later he has the most medals of all time , most gold . He increased the popularity of the sport in America through record - setting performances .