The Kentucky Derby, known as "The Most Exciting Two Minutes in Sports," is the top-ranking horse race in the US and has been held annually at Churchill Downs since the track's opening in 1875. It is the first and most iconic of the three races (the following two are the Preakness Stakes and the Belmont Stakes) that a horse must win to achieve the American Triple Crown. The race exclusively features three-year-old Thoroughbreds and has been 1-1/4 miles (or 2 kilometers) long since 1896. The Kentucky Derby has long been a venue at which great horses, such as Sir Barton, the first Triple Crown Winner, and Secretariat, the famed fastest runner, have been able to strut their stuff. In addition, the lavish and colorful outfits of the attendees, the betting and The Purse, and the tradition of Millionaire's Row - the expensive box seats that attracts the rich and elite - are as much part of the rich legacy of the event.