Mich. Comp. Laws § 551.2: Marriage as civil contract; consent; license; solemnization.

Sec. 2.

So far as its validity in law is concerned, marriage is a civil contract between a man and a woman, to which the consent of parties capable in law of contracting is essential. Consent alone is not enough to effectuate a legal marriage on and after January 1, 1957. Consent shall be followed by obtaining a license as required by section 1 of Act No. 128 of the Public Acts of 1887, being section 551.101 of the Michigan Compiled Laws, or as provided for by section 1 of Act No. 180 of the Public Acts of 1897, being section 551.201 of the Michigan Compiled Laws, and solemnization as authorized by sections 7 to 18 of this chapter.