When was the first tennis major comprising the Grand Slam before the US Open first held?
US Open (tennis) The United States Open Tennis Championships is a hard court tennis tournament. The tournament is the modern version of one of the oldest tennis championships in the world, the U.S. National Championship, for which men's singles was first contested in 1881. Since 1987, the US Open has been chronologically the fourth and final tennis major comprising the Grand Slam each year; the other three, in chronological order, are the Australian Open, the French Open and Wimbledon.
1991 ATP Tour The 1991 IBM ATP Tour was the elite tour for professional men's tennis organized by the ATP Tour. The IBM ATP Tour included the Grand Slam tournaments (organized by the International Tennis Federation (ITF)), the ATP Championship Series, Single-Week, the ATP Championship Series, the ATP World Series and the ATP Tour World Championships. The World Team Cup, Davis Cup (organized by the ITF) and Grand Slam Cup (organized by the ITF) are included in this calendar but did not count towards the Tour.