Bancroft County, Iowa was a county located in what today is the northern portion of Kossuth County. The county was established in 1851 by the Iowa General Assembly, but then abolished six years later in 1857 and the area joined to Kossuth County.
The county was named for George Bancroft (1800–1891), the historian.
There never was a county-seat established or the organization of a county government.
References
Bancroft County, Iowa Wikipedia(Text) CC BY-SA