# Iowa's 12th Senate district

The 12th District of the Iowa Senate is located in southern Iowa, and is currently composed of Adair, Clarke, Decatur, Lucas, Madison, and Wayne counties, as well as portions of Appanoose, Dallas, and Union counties.

## Current elected officials

Amy Sinclair is the senator currently representing the 12th District.
The area of the 12th District contains two Iowa House of Representatives districts:
* The 23rd District (represented by Ray Sorensen)
* The 24th District (represented by Joel Fry)
The district is also located in Iowa's 3rd congressional district, which is represented by U.S. Representative Zach Nunn.

## List of representatives

| Representative | Party | Dates | Residence | Notes |
| Loring Wheeler | Whig | 1846-1849 | Clinton County | |
| William Leffingwell | Democrat | 1850-1851 | Clinton County | |
| Norman Everson | Whig | 1852-1853 | Washington, Iowa | |
| Hiram Cleaver | Whig | 1854-1855 | Keokuk, Iowa | |
| James Test | Democrat | 1856-1857 | Council Bluffs, Iowa | |
| William H. M. Pusey | Democrat | 1858-1859 | Council Bluffs, Iowa | |
| Daniel Anderson | Republican | 1860-1861 | Monroe County | |
| Warren Dungan | Republican | 1862-1863 | Chariton, Iowa | |
| Jacob Dixon | Republican | 1864-1865 | Wapello County | |
| Edward Stiles | Republican | 1866-1867 | Ottumwa, Iowa | |
| Abial Pierce | Republican | 1868-1871 | Jefferson County | |
| Moses McCoid | Republican | 1872-1877 | Fairfield, Iowa | |
| Sanford Harned | Democrat | 1878-1881 | Keokuk County | |
| Cassius Brown | Republican | 1882-1885 | Sigourney, Iowa | |
| Joseph Hutchison | Republican | 1886-1887 | Ottumwa, Iowa | |
| James Dooley | Republican | 1888-1889 | What Cheer, Iowa | |
| Joel Stewart | Democrat | 1890-1893 | Grinnell, Iowa | |
| John Riggen | Republican | 1894-1897 | What Cheer, Iowa | |
| William Robinson Lewis | Republican | 1898-1901 | Montezuma, Iowa | |
| John Tinley Brooks | Republican | 1902-1906 | Sigourney, Iowa | |
| Elbert Clark | Republican | 1907-1910 | Grinnell, Iowa | |
| Henry Spaulding | Republican | 1911-1914 | Grinnell, Iowa | |
| Charles Laffer | Republican | 1915-1918 | Sigourney, Iowa | |
| Theodore Cessna | Republican | 1919-1926 | Grinnell, Iowa | |
| Frank Beatty | Republican | 1927-1934 | Sigourney, Iowa | |
| Eugene Mason | Democrat | 1935-1938 | Poweshiek County | |
| John Edwin Talbott | Republican | 1939-1942 | Brooklyn, Iowa | |
| Luke Vittetoe | Republican | 1943-1950 | Sigourney, Iowa | |
| Wilbur Molison | Republican | 1951-1958 | Poweshiek County | |
| C. Edwin Gilmour | Democrat | 1959-1962 | Grinnell, Iowa | |
| | | 1963-1964 | | No senator from district 12 is listed on the Iowa Official Register for General Assembly 60. This is the combined result of redistricting and election cycles and affected multiple districts. |
| Stanley Heaberlin | Democrat | 1965-1966 | Pleasantville, Iowa | |
| Joseph Flatt | Republican | 1967-1970 | Winterset, Iowa | Resigned from office due to moving out of his district. |
| Glen Bortell | Republican | 1970 | Madison County | |
| Alden Erskine | Republican | 1971-1972 | Woodbury County | |
| Clifton Lamborn | Republican | 1973-1976 | Maquoketa, Iowa | |
| Merlin Hulse | Republican | 1977-1982 | Cedar County | |
| Ted J. Anderson | Democrat | 1983-1984 | Waterloo, Iowa | |
| Joy Corning | Republican | 1985-1990 | Cedar Falls, Iowa | |
| Harry Slife | Republican | 1991-1994 | Waterloo, Iowa | Senator Slife died in office in 1994. |
| Donald Redfern | Republican | 1994-2002 | Cedar Falls, Iowa | |
| Kathleen Rehberg | Republican | 2003-2004 | Buchanan County | |
| Brian Schoenjahn | Democrat | 2005-2012 | Arlington, Iowa | |
| Joni Ernst | Republican | 2013-2014 | Red Oak, Iowa | Senator Ernst was elected to the US Senate in 2014. |
| Mark Costello | Republican | 2015-2022 | Imogene, Iowa | |
| Amy Sinclair | Republican | 2023-present | Wayne County | |

## Historical district boundaries

Source:
| Description | Years effective | Notes |
| Clinton County Scott County | 1846-1851 | From 1846 to 1857, district numbering was not utilized by the Iowa State Legislature. This convention was added with the passing of the 1857 Iowa Constitution. Numbering of districts pre-1857 is done as a matter of historic convenience. |
| Louisa County Washington County | 1852-1855 | |
| Audubon County Buena Vista County Carroll County Calhoun County Cherokee County Clay County Crawford County Dickinson County Emmet County Harrison County Ida County Lyon County Monona County O'Brien County Osceola County Palo Alto County Plymouth County Pocahontas County Pottawattamie County Sac County Shelby County Sioux County Woodbury County | 1856-1859 | Lyon County would have been known as Buncombe County during this period. |
| Lucas County Monroe County | 1860-1863 | |
| Wapello County | 1864-1867 | |
| Jefferson County | 1868-1877 | |
| Keokuk County | 1878-1883 | |
| Iowa County Keokuk County | 1884-1885 | |
| Wapello County | 1886-1887 | |
| Keokuk County Poweshiek County | 1888-1962 | |
| Marion County Warren County | 1963-1966 | |
| Adair County Cass County Madison County | 1967-1970 | |
| Woodbury County (partial) | 1971-1972 | In 1970, the Iowa Legislature passed an amendment to the Iowa Constitution setting forth the rules for legislative redistricting in order to abide by the rules established by the Reynolds v. Sims Supreme Court case. The first reapportionment map created by the Republican controlled legislature was deemed unconstitutional, but was still used for the 1970 election. |
| Cedar County Jackson County (partial) Johnson County (partial) Jones County (partial) Scott County (partial) | 1973-1982 | |
| Black Hawk County (partial) | 1983-1992 | |
| Black Hawk County (partial) | 1993-2002 | |
| Buchanan County Black Hawk County (partial) Barclay Township Big Creek Township Cedar Township Fox Township Poyner Township Spring Township Gilbertville La Porte City Clayton County Delaware County (partial) Coffins Grove Township Delaware Township Elk Township Honey Creek Township Oneida Township Richland Township Delaware Dundee Earlville Greeley Masonville Fayette County (partial) Fairfield Township Illyria Township Pleasant Valley Township Putnam Township Scott Township Smithfield Township Westfield Township Arlington Elgin Fairbank Fayette Wadena | 2003-2012 | |
| Fremont County Mills County Montgomery County Page County Ringgold County Taylor County | 2013-2022 | |
| Adair County Appanoose County (partial) Independence Township Johns Township Lincoln Township Plano Clarke County Dallas County (partial) Adams Township Colfax Township Union Township De Soto Earlham Redfield Decatur County Lucas County Union County (partial) Dodge Township Lincoln Township Jones Township New Hope Township Pleasant Township Lorimor Thayer | 2023-present | |