Mo. Const. art. III, § 48
The general assembly may enact laws and make appropriations to preserve and perpetuate memorials of the history of the state by parks, buildings, monuments, statues, paintings, documents of historical value or by other means, and to preserve places of historic or archaeological interest or scenic beauty, and for such purposes private property or the use thereof may be acquired by gift, purchase, or eminent domain or be subjected to reasonable regulation or control.