European tensions caused by the Russo-Japanese War and the difficulty of getting to St. Louis kept most of the world's top athletes away. Only 62 of the 651 athletes who competed came from outside North America, and only 12–15 nations were represented in all.
81% of all competitors were from the United States, and in 53 of the 95 events, the U.S. were the only country to field competitors; as such, some events combined the U.S. national championship with the Olympic championship.
The city of Chicago, Illinois won the bid to host the 1904 Summer Olympics, but the organizers of the Louisiana Purchase Exposition in St. Louis would not accept another international event in the same time frame.
The exposition organization began to plan for its own sports activities, informing the Chicago OCOG that its own international sports events intended to eclipse the Olympic Games unless they were moved to St. Louis. Pierre de Coubertin, the founder of the modern Olympic movement, stepped in and awarded the Games to St. Louis.
The St. Louis organizers treated the Games in a manner similar to the previous Olympiad, with competitions reduced to a side-show of the World's Fair and overshadowed by other, more popular cultural exhibits. David R. Francis, the President of the Louisiana Purchase Exposition, declined to invite anybody else to open the Games and on July 1 did so himself in a short, disorganised and poorly attended ceremony.