Which American tennis player was the only man to have won the US Open singles title on Grass, Clay and Hard Courts?

Answer 1

Jimmy Connors is the only individual to have won US Open singles titles on all three surfaces (grass, clay, hardcourt), while Chris Evert is the only woman to win on two surfaces (clay, hardcourt). The US Open is the only Grand Slam tournament that has been played every year since its inception.