Two years after taking up competitive swimming at the age of 12, Shelly Mann won the first of her 24 AAU titles. She won national championships in the freestyle, breaststroke, butterfly and individual medley events. At the 1955 Pan American Games she won bronze in the 100 m butterfly. Apart from her two medals at the 1956 Olympics, she also swam in the 100 m freestyle in Melbourne, placing sixth in the final. The versatile Miss Mann set world records in the butterfly (100 m and 200 m) and the individual medley, and in the heats of the 1956 U.S. Trials, she equalled the world record for the 100 m freestyle. Mann was a student at American University and a member of the Walter Reed Swim Club, where she was coached by Jim Campbell. She trained at daybreak in a hospital pool before it was needed by the patients who were swimming for rehabilitative purposes. Coincidentally, Miss Mann begain swimming for her rehabilitation from polio when she was a young child.