You can keep your wedding date secret, and you can marry your 13 year old sweetheart, if you can convince a Probate Court Judge. Obviously this seems kind of odd, and you probably never heard of this law, but it is right there in Michigan's Issuance of Marriage License Without Publicity Act 180 of of 1897.
That date helps explain the reasoning behind this law. Doing some research on this, I found that the purpose behind this law was to "protect the reputation of females" and for the "benefit of public morals." Another title for this law might have been "The Shotgun Wedding Act".
This law is still in place, and you could still request a secret marriage to a teenager. But these days, I'm not sure that a pregnant bride would be considered a great harm to her reputation. And I would hope that most judges would consider marrying 13 year olds as more harmful to public morals than allowing them to give birth unwed. But, there are still many Probate Court websites listing instructions for applying for secret marriages. So, maybe this is still a popular option? I've had no clients request a secret marriage, and haven't come across a secretly married client yet.
This law also, for some reason, explicitly refers to "couples of the opposite sex."I don't know if the original 1897 law said that, or if it was added in 1983 when the law was amended. The text of the amendment and original law aren't available online. But, this means there is yet another law for the State to amend now that same-sex marriage is legal.
Apparently, at one time when Michigan had no waiting period for wedding licenses, this law made St.Joseph, Michigan, a popular destination for weddings from Chicago. California is the only other state in the country with a secret marriage law, and they don't allow minors to marry in secret. So, Michigan is still unique with this law. This law also causes challenges for people researching family histories. MCL 333.2885 allows the state to transfer copies of 75 year old marriage licenses to libraries for genealogical research, but it excludes secret marriages, no matter how old.
So, if you're having trouble finding your great-grandparent's marriage license on Ancestry.com, maybe it's because they had a secret shotgun wedding?