Missouri Constitution
Article I - Bill of Rights
Section 28 Limitation on taking of private property for private use—exceptions—public use a judicial question.

That private property shall not be taken for private use with or without compensation, unless by consent of the owner, except for private ways of necessity, and except for drains and ditches across the lands of others for agricultural and sanitary purposes, in the manner prescribed by law; and that when an attempt is made to take private property for a use alleged to be public, the question whether the contemplated use be public shall be judicially determined without regard to any legislative declaration that the use is public.

Source: Const. of 1875, Art. I, Sec. 20.