Missouri Revised Statutes 1.010 provides:
1.010. 1. The common law of England and all statutes and acts of parliament made prior to the fourth year of the reign of James the First, of a general nature, which are not local to that kingdom and not repugnant to or inconsistent with the Constitution of the United States, the constitution of this state, or the statute laws in force for the time being, are the rule of action and decision in this state, any custom or usage to the contrary notwithstanding, but no act of the general assembly or law of this state shall be held to be invalid, or limited in its scope or effect by the courts of this state, for the reason that it is in derogation of, or in conflict with, the common law, or with such statutes or acts of parliament; but all acts of the general assembly, or laws, shall be liberally construed, so as to effectuate the true intent and meaning thereof.

Matter of Natale, 527 SW 2d 402 - Mo: Court of Appeals 1975 provides:
The law of England adopted by Section 1.010, supra, recognized the right to change name by the nonfraudulent use of another. The right was never limited to males; indeed, it was through this common law method that a woman changed her surname to that of her husband after marriage. Cowley v. Cowley, (1901) A.C. 450, 460; 19 Halsbury, Laws of England (3d ed.), p. 829; 32 Md.L.Rev. 409 (1972); Lamber, A Married Woman's Surname: Is Custom Law?, 1973 Wash.U.L.Q. 779. As Section 1.010, supra, does not purport to prohibit married females from exercising their common law rights, married women in Missouri are free to adopt another name by the common law method if this right has not been invalidated by constitutional or statutory mandate. This court is unaware of any constitutional or statutory provision which abrogates the English common law right to change names through usage, Section 417.200 (RSMo 1969, V.A.M.S.) notwithstanding.

Affidavit