On January 15, 1851, Gov. Stephen Hempstead approved an act of the Iowa legislation creating 50 new counties out of the unorganized territory in the Western portion of the state. One section of that act provided: "That the following shall be the boundaries of a new county to be called Winnebago." Winnebago County was officially organized and recognized in 1857 with election of officers. Winnebago County is comprised of 12 townships with a land mass of 408 sq. miles, equal to about 261,000 acres.
The county is named after the Winnebago Indian Tribe who inhabited this area in the 1800s. In 1853 white men came to hunt and trap and in 1855 Thomas Bearse became the first settler living on Lime Creek about 3/4 mi. east of this spot. The population of 1860 was 168 people. The courthouse was built in 1861, remodeled in 1877, torn down in 1896 and replaced by the present brick main structure in Jan. 1897 at a cost of $20,496. The south wing was added later.
The county population was 11,723 in 2000. Winnebago County celebrated it's sesquicentennial (150th) Birthday in 2005.
Iowa gained statehood 28 Dec, 1848 and is named after the Ioway Indian Tribe.