Actually, it may not be quite as straightforward as that.
Your profile says you’re in “ChigagObama”, so I had a quick look at the Illinois Marriage and Dissolution of Marriage Act: 750 ILCS 5/ Illinois Marriage and Dissolution of Marriage Act.
In large measure, it confirms what you say. Sec. 201: “A marriage between 2 persons licensed, solemnized and registered as provided in this Act is valid in this State.” So it seems as though all three steps are required for validity.
Licensing is something the couple attend to before the ceremony. We know that.
Solemnisation is the ceremony. Under sec. 209, leaving aside for a moment marriages before judges and county clerks and so forth, solemnisation can be “in accordance with the prescriptions of any religious denomination, Indian Nation or Tribe or Native Group, provided that when such prescriptions require an officiant, the officiant be in good standing with his or her religious denomination, Indian Nation or Tribe or Native Group.” For good “free exercise” reasons, the state makes no attempt to regulate how religious denominations, etc, conduct their marriage ceremonies; that’s a matter for them. There’s no requirement that signing any document should form part of the ceremony.
But there is a subsequent paperwork requirement. Within ten days after the solemnisation, either the officiant or the couple themselves must sign a marriage certificate form and forward it to the county clerk.
Finally, registration. Signing the certificate and forwarding it to the clerk is not registration. Under sec. 210, registration is what the clerk does after he receives the certificate.
So, three points from all this.
First, under Illinois law, registration apparent is required for a valid marriage.
Secondly, the officiant (or the couple) signing the paperwork, and sending or delivering it to the county clerk is not registration. Registration is what the clerk does with the paperwork he receives. Presumably, he enters the details from the marriage certificate from supplied to him into a register. Presumably also, depending on the flow of work within the office, that could happen some time after the paperwork is received at the office.
Thirdly, and most interestingly of all, one of the details set out in s. 210 the clerk has to register is “the date and place of the marriage”. Now, if registration is the necessary final step for their to be a valid marriage, there’s no marriage until the registration is complete, and therefore the date the clerk should enter as the date of the marriage is today’s date; i.e. the date he is making the entry in the register. Similarly the place where the marriage is completed is the county clerk’s own office, because that’s where registration takes place. But I’ll give you 20-to-1 on that, in fact, the date and place entered in the register is the date and place of solemnisation, not the date and place of registration. Notwithstanding that registration is required for validity, the marriage is in fact regarded as having taken place when solemnised.
There’s no case for saying, I think, that the date of the marriage is the date the officiant signed the paperwork. That will normally be the date of solemnisation, but if for some reason he doesn’t sign it for a couple of days, his signing it is neither solemnisation nor registration one of the three essential steps for validity of marriage.
I wouldn’t assume that other states have followed Illinois in making registration a requirement for validity. FWIW this site: http://www.usmarriagelaws.com/, attempting a broad summary of US laws, says:
“The person who performs the marriage ceremony has a duty to send a copy of the marriage certificate to the county or state agency that records marriage certificates. Failure to send the marriage certificate to the appropriate agency does not necessarily nullify the marriage, but it may make proof of the marriage more difficult.”
In general, in the common law world there’s a current in public policy which says that people’s status should be aligned with what that they think it is. If a couple have been through a marriage ceremony and consider themselves married and are considered married by their family and friends then probably the state ought to consider them married too, unless there is some compelling public interest against that. Ohio, to pick a state at random, imposes requirement on the officiant to send a marriage certificate to the probate judge within thirty days of solemnisation, and makes failure to do so a misdemeanour which attracts a penalty, but there is no provision saying that the marriage is invalid if this is not done.