Mexico is a town in the northeastern section of Oswego County, New York, United States. The population was 5,197 at the 2010 census. The town contains a village also named Mexico. Mexico has been referred to as the "Mother of Towns", as the original town as enacted by separate acts of 1792 and 1796 comprised an area that would eventually form six sep…Mexico is a town in the northeastern section of Oswego County, New York, United States. The population was 5,197 at the 2010 census. The town contains a village also named Mexico. Mexico has been referred to as the "Mother of Towns", as the original town as enacted by separate acts of 1792 and 1796 comprised an area that would eventually form six separate counties. These six counties today contain a total of 84 separate towns that were once included in the original Town of Mexico.