Mo. Rev. Stat. § 451.220
Current with changes from the 2023 Legislative Session
All marriage contracts whereby any estate, real or personal, in this state, is intended to be secured or conveyed to any person or persons, or whereby such estate may be affected in law or equity, shall be in writing, and acknowledged by each of the contracting parties, or proved by one or more subscribing witnesses.
§ 451.220, RSMo
RSMo 1939 § 3373