The Wisconsin Historical Society library houses a collection of Wisconsin session law books. Those aging little volumes hold answers to questions, but a trip to Madison is not necessary to peruse them.
The Advancing Genealogist has created an online library of links to digitized Wisconsin statutory law. Historic Wisconsin Statutes is a place to quickly locate digitized session laws books and compiled statutes.
Check the private acts volumes when seeking laws created for the good of individuals or small groups. (Sometimes public and private acts are published in the same volume, other times they are printed in separate books.) Did your ancestor have a mill or a ferry? They may have been granted a private act allowing them to operate their business. Was your Civil War veteran or his widow ineligible for a federal military pension until a more generous federal pension act came along? They may have been given a temporary state pension. Territorial acts include name changes and divorces.
Although Wisconsin has done a notable job of publishing old digitized laws on the state legislature’s website, the laws there are not easy to search. Each numbered session law stands alone within its session folder. If you do not know when your sought law was passed, good luck finding it. Session laws aren’t in a little book to browse on the state’s website. That’s one reason I collected links to books that can be easily browsed.
Enjoy researching in Wisconsin’s session laws. Don’t stay up too late!