Missouri is a land of many languages. English is most common, but there are significant populations of Bosnian-speakers in St. Louis, as well as an historical Francophone community in the eastern part of the state. Statewide, as is the case across the country, the second most common language spoken in Missouri homes (after English) is Spanish. However on the local level, that is not always the case.
In nearly twenty Missouri counties German is is the dominant second language. The German-speaking population in Missouri is two-fold. Some families speak Hermanndeutsch -- a local dialect centered around the city of Hermann, while Pennsylvania Dutch is spoken by the state's large Amish and Mennonite population.
Here's a county-by-county breakdown of Missouri's most common second languages: