Fayette Bremer Tama Marshall Benton / Adair Madison Warren Marion Mahaska / Harrison Audubon Shelby Guthrie Dallas / Shelby Guthrie Dallas Polk Jasper / Van Buren Lee / Floyd Chickasaw Winneshiek Allamakee Kossuth / Ida Monona / Calhoun Crawford Carroll Webster Hamilton / Clayton Buchanan Delaware Dubuque Grundy / Tama Marshall Benton Jones Linn Jackson Clinton / Warren Marion Mahaska Keokuk / Johnson Scott Muscatine Pottawattamie Cass Adair / Carroll Webster Hamilton Boone Greene / Clay Cherokee Palo Alto / Davis Jefferson Henry Des Moines Van Buren / Boone Greene Clayton Buchanan Delaware / Lucas Wayne Monroe Appanoose Wapello Davis Jefferson / Buena Vista Humboldt Pocahontas Wright / Clarke Decatur Lucas Wayne Monroe / /