Missouri constitution
Article I: bill of rights
Section 27

That in such manner and under such limitations as may be provided
by law, the state, or any county or city may acquire by eminent domain such
property, or rights in property, in excess of that actually to be occupied by the public
improvement or used in connection therewith, as may be reasonably necessary to effectuate
the purposes intended, and may be vested with the fee simple title thereto, or the
control of the use thereof, and may sell such excess property with such restrictions as
shall be appropriate to preserve the improvements made.