A good place to start researching your Midwestern roots, as with any US genealogy, is with the census. The good news is that the federal censuses for these states still exist, for the most part, from the time of their territorial formation. Some early Ohio censuses are no longer available, and the same is true for some individual counties or parts of counties in all these states for particular years. You'll find printed indexes to the federal censuses for these states for most years and a growing online and CD-ROM collection of indexes and actual census images. The Library of Michigan has a free online index to the Michigan 1870 federal census that even includes scanned images of the records.

Many also took state censuses; the majority of these were for years ending in 5. Iowa has state census records as late as 1925; that census lists everyone in the household. It even gives a county for those born in Iowa and the maiden name of the enumerated person's mother. Wisconsin and Minnesota have enumerations of everyone in the state as late as 1905. Minnesota Historical Society volunteers and staff members are indexing the 1895 every-name state census. Michigan has an 1894 state census, which tells how many children each woman had and how many were living. The rest of the states don't include this detail until the 1900 federal census. The 1894 Michigan census is full of valuable information, such as how many years a person resided in Michigan and in the United States.

If you have Ohio, Indiana, Missouri or Illinois ancestry, you won't have this same good fortune in state census research. Ohio and Indiana have some scattered enumerations of free white males. Missouri has some scattered state enumerations for early years. Illinois has some early state censuses, but many no longer exist. The most recent enumeration is for 1865. That year's and the 1855 enumeration survive for most counties.