The first International Congress of Mathematicians was held in Zürich in 1897 with 208 mathematicians from 18 countries attending. It was followed by a sequence of Congresses: Paris (1900); Heidelberg (1904); Rome (1908); and Cambridge, England (1912). After World War I, there was a conference in London to decide upon the future of international scientific relationships. It determined that for the foreseeable future there could be no collaboration between scientists of the Allied countries (the Entente Cordiale) and those of Germany and its allies (the Central Powers).

In 1920, American L.E. Dickson proposed that the next Congress, scheduled for 1924, should be held in the United States, away from the bitter post-war atmosphere of Europe. His invitation was accepted, but it ran into trouble over the question of whom to invite. The French would not attend a Congress that included Germans. At a meeting where John Charles Fields was present, a quiet suggestion arose that perhaps the 1924 Congress could be held in Canada. Fields was enthusiastic; he thought he could arrange a Congress in Toronto, and the Americans were relieved to be rid of it.

Thus, first by default and then through the enthusiasm and hard work of Fields and his colleagues, the 1924 International Mathematical Congress came to Toronto.