US Open only Grand Slam to have been played on all surfaces 
The US Open is the only Grand Slam to have been played on all the three surfaces, starting with grass from 1881-1974. From 1975-1977, the season's last Grand Slam was played on clay before being shifted to a hard-court surface in 1978. Notably, Jimmy Connors is the only player to have won the US Open on all the three surfaces.