Recently I read an article in Family Tree Magazine, "Getting More from the Census", December 2014. While the article had some great idea's for clues, one thing was missing, State Census's.
Federal census's were taken every 10 years, starting in 1820, Wisconsin State Census were taken in between federal census, ending in a 5. This is a great help for filling in the gap of the 1890 destroyed Federal census.
The Wisconsin State census, that I have viewed do not have a lot of detailed information, but are useful for finding when and where a person lived, who the head of the household was, and how many males and females were in the household.
Territorial census covered: 1836, 1838, 1842, 1846, 1847
Wisconsin State covered: 1855, 1875, 1885, 1895, 1905
The 1905 census being the most useful, as the whole household was enumerated.
When I use the State census, I tend to go page by page, instead of relying on a index, due to the many variations of spellings, of my Polish ancestors, who lived in Portage county. This also gives me a better feel for who the neighbors were, which often are relatives, with misspelled names.
The Family search library has the 1855, 1865, 1875,1895, 1905 census available on line and has detailed information about all of the Wisconsin census.
1820 to 1855 does not appear to be on line, as you are directed to World Cat, or the Wisconsin State Historical Society or National Archives.
1905 was the final year for Wisconsin's census, due to a change in the state constitution in 1907. 
Below is a link to some of Family Search's Wisconsin census.
The following link has indexed some of the Wisconsin counties, while not complete it can be a great help in narrowing a search:
Following is a link to the Wisconsin Mortality Schedules:
Link to Wisconsin Historical Society-Wisconsin Census Enumeration 1895. Names of Ex-Soldiers and Sailors Residing in Wisconsin, June, 20 1895.
1.Wisconsin Historical Society. Wisconsin Local History & Biography Articles; "Newspaper"; "Ripon", "Wisconsin"; " 1 April 1915"; viewed online at http://www.wisconsinhistory.org on [31 December 2014]