Delaware County, Iowa

Delaware County, Iowa
The Delaware County Courthouse in Manchester
Location within the U.S. state of Iowa
Coordinates: 42°28′10″N 91°22′13″W / 42.469444444444°N 91.370277777778°W / 42.469444444444; -91.370277777778
Country United States
State Iowa
FoundedDecember 21, 1837 (created)
February 8, 1844 (organized)[1]
Named afterState of Delaware
SeatManchester
Largest cityManchester
Area
 • Total
579 sq mi (1,500 km2)
 • Land578 sq mi (1,500 km2)
 • Water1.2 sq mi (3.1 km2)  0.2%
Population
 (2020)
 • Total
17,488
 • Estimate 
(2024)
17,609
 • Density30.3/sq mi (11.7/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional district2nd
Websitedelawarecounty.iowa.gov
  • Iowa county number 28[2]

Delaware County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 17,488.[3] The county seat is Manchester.[4] The county takes its name after the U.S. state of Delaware.

Geography

According to the U.S. Census Bureau, the county has a total area of 579 square miles (1,500 km2), of which 578 square miles (1,500 km2) is land and 1.2 square miles (3.1 km2) (0.2%) is water.[5] It has a rough hilly surface.[6]

Major highways

Adjacent counties

Demographics

Historical population
CensusPop.Note
18501,759
186011,024526.7%
187017,43258.1%
188017,9503.0%
189017,349−3.3%
190019,18510.6%
191017,888−6.8%
192018,1831.6%
193018,122−0.3%
194018,4872.0%
195017,734−4.1%
196018,4834.2%
197018,7701.6%
198018,9330.9%
199018,035−4.7%
200018,4042.0%
201017,764−3.5%
202017,488−1.6%
2024 (est.)17,609[7] 0.7%
U.S. Decennial Census[8]
1790–1960[9] 1900–1990[10]
1990–2000[11] 2010–2020[12]

2020 census

As of the 2020 census, the county had a population of 17,488, resulting in a population density of 30.2/sq mi (11.7/km2).[13]

As of the 2020 census, the median age was 43.5 years. 23.6% of residents were under the age of 18 and 20.5% of residents were 65 years of age or older. For every 100 females there were 101.8 males, and for every 100 females age 18 and over there were 99.6 males age 18 and over.[13]

As of the 2020 census, the racial makeup of the county was 96.0% White, 0.7% Black or African American, 0.3% American Indian and Alaska Native, 0.3% Asian, <0.1% Native Hawaiian and Pacific Islander, 0.5% from some other race, and 2.3% from two or more races; Hispanic or Latino residents of any race comprised 1.4% of the population.[14] 97.75% of residents reported being of one race, including 94.60% who were non-Hispanic White and 0.70% who were Black or African American, while 2.74% reported being some other race or more than one race.[14]

As of the 2020 census, 28.1% of residents lived in urban areas, while 71.9% lived in rural areas.[15]

As of the 2020 census, there were 7,141 households in the county, of which 27.8% had children under the age of 18 living in them. Of all households, 57.4% were married-couple households, 17.8% were households with a male householder and no spouse or partner present, and 19.7% were households with a female householder and no spouse or partner present. About 27.5% of all households were made up of individuals and 13.0% had someone living alone who was 65 years of age or older. There were 8,100 housing units, of which 11.8% were vacant, leaving 7,141 occupied units; among the occupied units, 80.2% were owner-occupied and 19.8% were renter-occupied. The homeowner vacancy rate was 1.6% and the rental vacancy rate was 6.8%.[13]

2010 census

The 2010 census recorded a population of 17,764 in the county, with a population density of 30.7/sq mi (11.9/km2). There were 8,028 housing units, of which 7,062 were occupied.[16]

2000 census

As of the census[17] of 2000, there were 18,404 people, 6,834 households, and 5,029 families residing in the county. The population density was 32 people per square mile (12 people/km2). There were 7,682 housing units at an average density of 13 units per square mile (5.0 units/km2). The racial makeup of the county was 99.28% White, 0.07% Black or African American, 0.10% Native American, 0.14% Asian, 0.01% Pacific Islander, 0.10% from other races, and 0.30% from two or more races. 0.66% of the population were Hispanic or Latino of any race.

There were 6,834 households, out of which 36.70% had children under the age of 18 living with them, 64.10% were married couples living together, 6.20% had a female householder with no husband present, and 26.40% were non-families. 23.00% of all households were made up of individuals, and 11.20% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.15.

In the county, the population was spread out, with 29.00% under the age of 18, 7.00% from 18 to 24, 27.60% from 25 to 44, 21.50% from 45 to 64, and 15.00% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 98.40 males. For every 100 females age 18 and over, there were 96.60 males.

The median income for a household in the county was $37,168, and the median income for a family was $43,607. Males had a median income of $30,712 versus $19,685 for females. The per capita income for the county was $17,327. About 6.30% of families and 7.90% of the population were below the poverty line, including 8.50% of those under age 18 and 9.80% of those age 65 or over.

Communities

Cities

Townships

Delaware County is divided into these townships:

Unincorporated communities

Population ranking

The population ranking of the following table is based on the 2020 census of Delaware County.[3]

county seat

Rank City/Town/etc. Municipal type Population (2020 Census)
1 Manchester City 5,065
2 Dyersville (mostly in Dubuque County) City 4,477
3 Edgewood (partially in Clayton County) City 909
4 Earlville City 716
5 Hopkinton City 622
6 Delhi City 420
7 Colesburg City 386
8 Ryan City 350
9 Greeley City 217
10 Dundee City 198
11 Delaware City 142
12 Masonville City 99

Politics

United States presidential election results for Delaware County, Iowa[18]
Year Republican Democratic Third party(ies)
No.  % No.  % No.  %
1896 2,799 60.52% 1,778 38.44% 48 1.04%
1900 2,805 63.02% 1,570 35.27% 76 1.71%
1904 2,726 67.04% 1,236 30.40% 104 2.56%
1908 2,396 60.35% 1,471 37.05% 103 2.59%
1912 1,394 34.30% 1,399 34.42% 1,271 31.27%
1916 2,827 66.78% 1,332 31.47% 74 1.75%
1920 5,880 82.96% 1,111 15.67% 97 1.37%
1924 4,938 64.68% 1,146 15.01% 1,551 20.31%
1928 5,390 63.74% 3,043 35.99% 23 0.27%
1932 4,088 46.70% 4,559 52.08% 107 1.22%
1936 4,483 49.56% 4,350 48.09% 213 2.35%
1940 6,175 67.30% 2,985 32.53% 16 0.17%
1944 5,164 67.22% 2,498 32.52% 20 0.26%
1948 4,555 60.75% 2,876 38.36% 67 0.89%
1952 6,449 73.20% 2,351 26.69% 10 0.11%
1956 5,732 68.49% 2,621 31.32% 16 0.19%
1960 5,015 57.62% 3,688 42.38% 0 0.00%
1964 3,427 42.49% 4,623 57.32% 15 0.19%
1968 4,650 59.39% 2,760 35.25% 419 5.35%
1972 4,848 61.21% 2,944 37.17% 128 1.62%
1976 4,161 55.62% 3,168 42.35% 152 2.03%
1980 4,316 55.38% 2,671 34.27% 807 10.35%
1984 4,769 59.61% 3,158 39.47% 74 0.92%
1988 3,425 46.08% 3,947 53.11% 60 0.81%
1992 3,195 37.62% 3,093 36.42% 2,204 25.95%
1996 3,065 40.88% 3,704 49.41% 728 9.71%
2000 4,273 51.18% 3,808 45.61% 268 3.21%
2004 4,908 53.35% 4,227 45.95% 65 0.71%
2008 4,113 46.20% 4,649 52.22% 141 1.58%
2012 4,636 49.43% 4,616 49.22% 126 1.34%
2016 5,694 61.62% 2,957 32.00% 590 6.38%
2020 6,666 66.64% 3,157 31.56% 180 1.80%
2024 6,984 68.89% 2,978 29.37% 176 1.74%

See also

References

  1. ^ "Iowa: Individual County Chronologies". publications.newberry.org. The Newberry Library. 2007. Retrieved December 28, 2025.
  2. ^ "Iowa County Names and Numbers". Iowa Department of Administrative Services. Retrieved December 28, 2025.
  3. ^ a b "2020 Census State Redistricting Data". census.gov. United states Census Bureau. Retrieved August 12, 2021.
  4. ^ "Find a County". National Association of Counties. Retrieved December 28, 2025.
  5. ^ "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. February 12, 2011. Retrieved April 23, 2011.
  6. ^ Ripley, George; Dana, Charles A., eds. (1879). "Delaware, the name of five counties in the United States. V. An E. county of Iowa" . The American Cyclopædia.
  7. ^ "County Population Totals and Components of Change: 2020-2024". Retrieved July 24, 2025.
  8. ^ "U.S. Decennial Census". United States Census Bureau. Retrieved January 7, 2014.
  9. ^ "Historical Census Browser". University of Virginia Library. 2007. Archived from the original on December 12, 2009. Retrieved January 7, 2014.
  10. ^ Forstall, Richard L. (April 20, 1995). "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Archived from the original on February 19, 1999. Retrieved January 7, 2014.
  11. ^ "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. Archived (PDF) from the original on March 27, 2010. Retrieved January 7, 2014.
  12. ^ "U.S. Census Bureau QuickFacts: Delaware County, Iowa". www.census.gov. Retrieved December 28, 2025.
  13. ^ a b c "2020 Decennial Census Demographic Profile (DP1)". United States Census Bureau. 2021. Retrieved December 25, 2025.
  14. ^ a b "2020 Decennial Census Redistricting Data (Public Law 94-171)". United States Census Bureau. 2021. Retrieved December 25, 2025.
  15. ^ "2020 Decennial Census Demographic and Housing Characteristics (DHC)". United States Census Bureau. 2023. Retrieved December 25, 2025.
  16. ^ "Population & Housing Occupancy Status 2010" (PDF). United States Census Bureau American FactFinder. Archived (PDF) from the original on October 16, 2020. Retrieved August 15, 2022.
  17. ^ "U.S. Census website". United States Census Bureau. Retrieved January 31, 2008.
  18. ^ Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Retrieved April 25, 2018.

42°28′10″N 91°22′13″W / 42.46944°N 91.37028°W / 42.46944; -91.37028