Company Story
1902 - Ameren Corporation was founded as Union Electric Company of Missouri.
1922 - The company was renamed Union Electric Company.
1931 - Union Electric Company merged with Missouri Edison Electric Company.
1947 - The company began to expand its operations into Illinois.
1953 - Union Electric Company merged with Illinois Power Company.
1963 - The company was renamed Ameren Corporation.
1997 - Ameren Corporation merged with CILCORP Inc.
2003 - Ameren Corporation acquired Illinois Power Company.
2010 - Ameren Corporation acquired Central Illinois Public Service Company.
2012 - Ameren Corporation sold its generating facilities to Dynegy Inc.