The International Geological Congress (IGC), originally the International Congress of Geologists, was founded on August 25, 1876, at the 25th Meeting of the American Association for the Advancement of Science, held in Buffalo, New York. The founding committee was composed of participants from the USA and Canada, with the addition of two geologists from Sweden and The Netherlands. Why did it take so many years after its establishment for the countries represented in the founding committee to host the IGC, beginning with the 5th IGC, held in Washington D.C. in 1893? The answer may be in documents, which point to the idea of the IGC originating from Giovanni Capellini as a result of his journeys in Europe and North America, especially through discussions with his French and Swiss friends. Capellini was the first titular chair of geology funded by the new-born Italian state in Bologna. European travels reinforced Capellini’s intention to create a great geological museum designed to store types and standards of fossils, rocks, lithic tools, and materials used for geological mapping, mining exploration, land planning, and improving agriculture. His long geological travel through North America in 1863 allowed Capellini to convey to many North American geologists his conviction that there was need for an international forum to reach a wide agreement on stratigraphy, palaeontology and mapping. During his 1863 trip, Capellini became a friend of three future members of the IGC founding committee and familiar with two others through common acquaintances. Perhaps, the Italian-French group of leading figures who first conceived of the IGC asked their North American colleagues to make a proposal from abroad. This same successful procedure of an ‘outside’ request was followed in founding the International Congress of Anthropology and pre-Historical Archaeology in 1865. The idea came from French scientists who confidentially asked Capellini to found the congress and suggested to hold the first session in Neuchâtel in 1866 and the second in Paris in 1867. This then may be the key to understanding why the first four IGCs were held in France, Italy, Germany, and UK before one took place in the USA where the IGC was founded.