The Central Illinois Public Service Company was an electric streetcar holding company and power utility first organized in 1902. Under its later quarter billion dollar holding company CIPSCO Inc. it merged in 1997 with the larger neighboring Union Electric Company of Missouri to form Ameren Corporation based in St. Louis Missouri. Now a subsidiary AmerenCIPS is headquartered in Springfield IL. http:--www. hoovers. com-free-search-simple-xmillion-index.