Linn County | |
|---|---|
Linn County Courthouse (2020) | |
Location within the U.S. state of Kansas | |
Kansas's location within the U.S. | |
| Coordinates: 38°13′00″N 94°51′00″W / 38.2167°N 94.85°W | |
| Country | |
| State | |
| Founded | February 26, 1867 |
| Named for | Lewis F. Linn |
| Seat | Mound City |
| Largest city | Pleasanton |
| Area | |
| • Total | 606 sq mi (1,570 km2) |
| • Land | 594 sq mi (1,540 km2) |
| • Water | 12 sq mi (30 km2) 2.0% |
| Population (2020) | |
| • Total | 9,591 |
| • Density | 16.1/sq mi (6.2/km2) |
| Time zone | UTC−6 (Central) |
| • Summer (DST) | UTC−5 (CDT) |
| Congressional district | 2nd |
| Website | linncountyks |
Linn County (county code LN) is a county in east-central Kansas. In 2020, 9,591 people lived there. Its county seat is Mound City. Its biggest city is Pleasanton. The county was named after Lewis F. Linn, a U.S. Senator from Missouri.
Explorers in the early 19th century found abandoned mining sites along a creek south of the Marais des Cygnes river. No one knows who the miners were. Early residents of the region decided to call the waterway "Mine Creek."
The U.S. Census Bureau says that the county has a total area of 606 square miles (1,570 km2). Of that, 594 square miles (1,540 km2) is land and 12 square miles (31 km2) (2.0%) is water.
| Historical population | |||
|---|---|---|---|
| Census | Pop. | %± | |
| 1860 | 6,336 | — | |
| 1870 | 12,174 | 92.1% | |
| 1880 | 15,298 | 25.7% | |
| 1890 | 17,215 | 12.5% | |
| 1900 | 16,689 | −3.1% | |
| 1910 | 14,735 | −11.7% | |
| 1920 | 13,815 | −6.2% | |
| 1930 | 13,534 | −2.0% | |
| 1940 | 11,969 | −11.6% | |
| 1950 | 10,053 | −16.0% | |
| 1960 | 8,274 | −17.7% | |
| 1970 | 7,770 | −6.1% | |
| 1980 | 8,234 | 6.0% | |
| 1990 | 8,254 | 0.2% | |
| 2000 | 9,570 | 15.9% | |
| 2010 | 9,656 | 0.9% | |
| 2020 | 9,591 | −0.7% | |
| U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2020 | |||

Linn County is included in the Kansas City, MO-KS Metropolitan Statistical Area.
| Year | Republican | Democratic | Third Parties |
|---|---|---|---|
| 2020 | 80.2% 4,048 | 17.8% 896 | 2.0% 102 |
| 2016 | 78.2% 3,484 | 16.5% 736 | 5.3% 234 |
| 2012 | 71.1% 3,177 | 26.2% 1,170 | 2.7% 120 |
| 2008 | 66.8% 3,086 | 30.9% 1,425 | 2.3% 106 |
| 2004 | 64.3% 3,048 | 34.4% 1,631 | 1.3% 62 |
| 2000 | 59.0% 2,513 | 37.3% 1,587 | 3.7% 159 |
| 1996 | 49.0% 2,077 | 37.5% 1,590 | 13.4% 568 |
| 1992 | 34.2% 1,413 | 32.8% 1,353 | 33.0% 1,365 |
| 1988 | 58.6% 2,163 | 40.6% 1,497 | 0.8% 31 |
| 1984 | 70.3% 2,795 | 29.0% 1,152 | 0.7% 27 |
| 1980 | 64.9% 2,407 | 31.2% 1,157 | 3.9% 146 |
| 1976 | 52.0% 1,873 | 46.7% 1,681 | 1.3% 48 |
| 1972 | 73.4% 2,593 | 24.8% 876 | 1.8% 63 |
| 1968 | 63.1% 2,250 | 25.1% 893 | 11.8% 422 |
| 1964 | 52.7% 1,939 | 46.9% 1,725 | 0.4% 15 |
| 1960 | 70.2% 2,824 | 29.2% 1,176 | 0.6% 24 |
| 1956 | 71.6% 2,991 | 28.2% 1,177 | 0.2% 7 |
| 1952 | 74.0% 3,527 | 25.6% 1,220 | 0.4% 20 |
| 1948 | 60.5% 2,632 | 38.4% 1,673 | 1.1% 49 |
| 1944 | 68.5% 3,185 | 31.0% 1,442 | 0.4% 20 |
| 1940 | 66.0% 4,086 | 33.4% 2,067 | 0.6% 34 |
| 1936 | 58.8% 3,872 | 40.7% 2,682 | 0.5% 33 |
| 1932 | 44.5% 2,647 | 54.0% 3,216 | 1.5% 90 |
| 1928 | 75.2% 4,231 | 23.6% 1,328 | 1.2% 68 |
| 1924 | 57.9% 3,161 | 30.8% 1,683 | 11.3% 614 |
| 1920 | 62.8% 3,189 | 34.8% 1,764 | 2.4% 122 |
| 1916 | 45.5% 2,699 | 49.4% 2,930 | 5.2% 307 |
| 1912 | 24.0% 858 | 35.8% 1,283 | 40.2% 1,441 |
| 1908 | 51.8% 1,950 | 44.0% 1,657 | 4.2% 158 |
| 1904 | 62.5% 2,324 | 29.2% 1,085 | 8.3% 307 |
| 1900 | 52.2% 2,279 | 46.8% 2,043 | 0.9% 41 |
| 1896 | 46.6% 2,153 | 52.5% 2,424 | 0.8% 39 |
| 1892 | 49.4% 2,046 | 50.6% 2,098 | |
| 1888 | 52.5% 2,166 | 19.4% 802 | 28.1% 1,157 |
