Union Electric Light and Power Company was an electric utility company that operated in the United States in the late 19th and early 20th centuries. The company was founded in 1893 in St. Louis, Missouri, and initially provided electric lighting and power to customers in the city and surrounding areas. In the 1920s, the company built the Bagnell Dam on the Osage River, which created the Lake of the Ozarks and provided hydroelectric power to the region. The dam and lake were major engineering projects at the time and helped to spur economic development in the area.
The Lake of the Ozarks in Missouri was created by the construction of the Bagnell Dam on the Osage River in the early 1920s. The dam was built by the Union Electric Light and Power Company, which later became Ameren Missouri, as a hydroelectric power generation facility. The lake was created by impounding the water behind the dam, which caused the water level to rise and flood the valley downstream. The construction of the dam and the creation of the lake were major engineering feats at the time and required the relocation of several communities and the rerouting of several roads and railroads. The Lake of the Ozarks is now a popular recreational destination, with more than 1,000 miles of shoreline and numerous marinas, campgrounds, and resorts.
In the 1930s and 1940s, Union Electric expanded its operations to include natural gas distribution and the production of coke and other by-products. The company also acquired several smaller electric and gas utilities in Missouri and Illinois. In the 1950s and 1960s, Union Electric continued to grow through acquisitions and mergers, and it became one of the largest electric and gas utilities in the Midwest. In 1997, Union Electric merged with Central Illinois Public Service Company to form Ameren Corporation, which is now one of the largest energy companies in the United States.