Extremely rare participation medal issued for the St. Louis 1904 Summer Olympics. Copper, 40 mm, 30 gm, by Dieges & Clust, New York. The front, inscribed, “Olympic Games, St. Louis, USA, 1904,” features an idealized nude athlete mid-stride with a laurel branch in his hand; the reverse features the lengthy text, “1803, Universal Exposition Commemorating the Olympic Games, 1904, Physical Culture Department, Frederick J. V. Skiff, Director of Exhibits,” encircled by ivy leaves with the shield emblems of St. Louis, France, and USA. These medals were presented only to athletes and represent the rarest and most valuable of all Olympic participation medals. Fewer than 700 athletes from twelve different countries competed in the 1904 Olympic Games, the smallest representation of nations in the history of the Olympics. The officials’ badges used the same design as this medal but had a loop on the top for a ribbon, while these athletes’ participation medals have an entirely plain edge. Because the Olympics were held in conjunction with the Louisiana Purchase Exposition, these are also desired by World’s Fair collectors. Overall, this is a spectacular example of the most sought-after Olympic participation medal.