This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The first World Cup, held in Uruguay in 1930, drew just thirteen teams, and getting even that many to South America was its own achievement. Several European federations initially declined to send teams at all, citing the several weeks a transatlantic sea voyage would cost their players; only four European sides ultimately made the crossing. The tournament's format grew only gradually afterward: sixteen teams became the standard field for most of the twentieth century, expanding to twenty four in 1982 and to thirty two in 1998, a size the tournament held for nearly three decades.
Television transformed the tournament's reach long before its bracket grew. The 1966 tournament in England was the first broadcast internationally by satellite, and color broadcasts followed at the 1970 tournament in Mexico, reaching audiences far beyond the stadiums for the first time. Commercial sponsorship and broadcast rights fees grew alongside that audience, turning a tournament that paid its 1930 participants nothing beyond travel expenses into one of the most heavily commercialized events in world sport.
The most recent expansion arrived at the 2026 tournament, co-hosted for the first time by three nations, the United States, Canada and Mexico, and enlarged to forty eight teams, the tournament's largest field yet and its first structural change to the format since 1998.