The 1904 Summer Olympics, officially known as the Games of the III Olympiad, was an international multi-sport event which was celebrated in St. Louis, Missouri, in the United States from August 29 until September 3, 1904, as part of an extended sports program lasting from July 1 to November 23, 1904, at what is now known as Francis Field on the campus of Washington University in St. Louis. It was the first time that the Olympic Games were held in a majority English language nation, and the first time that they were held outside of Europe.
The city of Chicago, Illinois originally 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, gave in and awarded the games to St. Louis.
- Basketball , Hurling and Baseball were featured as demonstration sports. Water polo is mentioned in the games reports for the 1904 Summer Olympics but currently is not included in the IOC's medal database and retrospectively considered by IOC as demonstration sport as well.
- Creve Coeur Lake – Rowing
- Francis Field – Archery, Athletics, Cycling, Football, Gymnastics, Lacrosse, Roque, Tennis, Tug of war, Weightlifting, and Wrestling
- Francis Gymnasium – Boxing, Fencing
- Forest Park – Diving, Swimming, and Water polo.
- Glen Echo Country Club – Golf
Athletes from twelve nations competed in St. Louis. Numbers in parentheses indicate the number of known competitors for each nation. Due to the difficulty of getting to St. Louis, and since the Russo-Japanese War caused European tensions, only 52 athletes from outside of North America came to the Olympics.
- 22x20px Australia (3)
- [[Image:Template:Country flag IOC alias AUT|22x20px|border|alt=|link=]] Austria (2)
- Canada (56)
- [[Image:Template:Country flag IOC alias CUB|22x20px|border|alt=|link=]] Cuba (3)
- [[Image:Template:Country flag IOC alias FRA|22x20px|border|alt=|link=]] France (1) 
- 22x20px Germany (22)
- [[Image:Template:Country flag IOC alias GBR|22x20px|border|alt=|link=]] [[Template:Country IOC alias GBR at the 1904 Summer Olympics|Template:Country IOC alias GBR]] (6)
- [[Image:Template:Country flag IOC alias GRE|22x20px|border|alt=|link=]] Greece (14)
- Hungary (4)
- [[Image:Template:Country flag IOC alias RSA|22x20px|border|alt=|link=]] South Africa (8)
- [[Image:Template:Country flag IOC alias SUI|22x20px|border|alt=|link=]] Switzerland (2)
- 22x20px United States (526)
Script error These are the top ten nations to win medals at the 1904 Games.
|1||22x20px United States (host nation)||79||81||80||240|
|3||[[Image:Template:Country flag IOC alias CUB|22x20px|border|alt=|link=]] Cuba||4||2||3||9|
|6||[[Image:Template:Country flag IOC alias GBR|22x20px|border|alt=|link=]] [[Template:Country IOC alias GBR at the 1904 Summer Olympics|Template:Country IOC alias GBR]]||1||1||0||2|
|[[Image:Template:Country flag IOC alias ZZX|22x20px|border|alt=|link=]] Mixed team||1||1||0||2|
|8||[[Image:Template:Country flag IOC alias GRE|22x20px|border|alt=|link=]] Greece||1||0||1||2|
|[[Image:Template:Country flag IOC alias SUI|22x20px|border|alt=|link=]] Switzerland||1||0||1||2|
|10||[[Image:Template:Country flag IOC alias AUT|22x20px|border|alt=|link=]] Austria||0||0||1||1|
The nationalities of many medalists are disputed as many competitors were recent immigrants to the United States who had not yet been granted US citizenship.
In 2009, historians from the International Society of Olympic Historians discovered that cyclist Frank Bizzoni formerly thought to be an American athlete was still an Italian citizen when he competed in 1904. 
The International Olympic Committee considers Norwegian-American wrestlers Charles Ericksen and Bernhoff Hansen to have competed for the United States; each won a gold medal. In 2012, Norwegian historians however found documentation showing that Ericksen did not receive American citizenship until March 22, 1905, and that Hansen, who was registered as an "alien" as late as 1925, probably never received American citizenship. The historians have therefore petitioned to have the athletes registered as Norwegians. In May 2013 it was reported that the Norwegian Olympic Committee had filed a formal application for changing the nationality of the wrestlers in IOC's medal database.
The IOC also lists French-American Albert Corey as a United States competitor for his marathon silver medal, but (together with four undisputed Americans) as part of a mixed team for the team race silver medal. Other sources list these athletes as competitors for their country of birth rather than the United States.
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