The Pan American Games are a multi sport event held every four years between competitors from all Nations of the Americas. The 1st Games were scheduled to be staged in Buenos Aires in 1943, but World War II caused them to be postponed until 1951. The 2007 Pan American Games will be held in Rio de Janeiro, Brazil from July 13 to July 29.
Water Polo has been present to the Pan American Games since the 1st edition held in Buenos Aires, Argentina in 1951.
The first eight editions and the Water Polo winners: Buenos Aires, Argentina 1951: Argentina, Brazil, USA; Mexico City, Mexico, 1955: Argentina, USA, Brazil; Chicago, USA 1959: USA, Argentina, Brazil; Sao Paulo, Brazil, 1963: Brazil, USA, Argentina; Winnipeg, Canada 1967: USA, Brazil, Mexico; Cali, Colombia, 1971: USA, Cuba, Mexico; Mexico City, Mexico 1975: Mexico, USA, Cuba; San Juan, Puerto Ric0 1979: USA, Cuba, Canada
Source: http://www.hickoksports.com/, and various