A largely rural and agricultural county, Winneshiek County has a rich cultural history from Czech, Slovak, English, Irish, German, Swiss, and Norwegian immigrants that have settled within its boundaries.
The county was originally settled in 1848 in present-day Bloomfield Township (near Castalia, Iowa) and in Washington Township (near Fort Atkinson, Iowa). It was organized in 1847, and named after a chief of the Winnebago tribe.
In 1980, Winneshiek County reported a population of 21,842. Like much of Iowa during the 1980s it witnessed a population loss, dropping to 20,847 according to the 1990 United States Census. However, during the 1990s the county experienced some mild growth and was able to rise above the 21,000 mark once again.