To win the Triple Crown, a horse must compete in three long races, at three different tracks, in three different states in a span of five weeks starting with the Kentucky Derby held at Churchill Downs in Louisville, KY. The Kentucky Derby itself began in 1875 - today it is the longest continuously running sporting event. It is the world's most famous horse race and is the first of three races for three-year-old horses that make up the Triple Crown of Horse Racing. Known as the "Run For The Roses", more than 100,000 spectators are drawn to the 1 1/4 mile race that takes place the first Saturday in May (2008 race to be held on May 3rd). Only eleven horses have won the Triple Crown, some of those famous names are: Affirmed, Seattle Slew, Secretariat, Citation, Assault.