Wentzville was founded in 1855.   A railroad was pushing across Missouri to the west to carry settlers and to furnish services for those few who were already established in the new area. This movement prompted William M. Allen, a great land owner and slaveholder in Western St. Charles County, to give a tract of land along the railroad right-of-way to establish a station to serve the local community. Mr. Allen laid out the town, which consisted of a narrow tract of ground seven blocks long lying east and west along the railroad. In giving the ground for the first railroad station, he stipulated in the grant that in the event the station was moved or taken away, the land would revert to his heirs. This assured the station’s site for the community and made the new town’s future more secure.

Mr. Erasmus Livingston Wentz of New York State helped Mr. Allen in surveying the present town’s lots and streets and so Mr Allen honored his good friend Mr. Wentz by naming the town after him.