"Mattoon is a city in Coles County, Illinois, United States. The population was 18,555 as of the 2010 census. It is a principal city of the Charleston\u2013Mattoon Micropolitan Statistical Area.Mattoon was the site of the \"Mad Gasser\" attacks of the 1940s."@en . . "Mattoon"@en . . . . . . . . . "18555"^^ . "223.114"^^ . . . . . "217" . "61938" .