The first county seat of Wahkaw County was the now-extinct village of Thompsonville; when the Legislature changed the county name to Woodbury, the new county seat became Sergeant's Bluff (nowSergeant Bluff). The county seat was moved to Sioux City in 1856.
The Winnebago Tribe of Nebraska (Ho-Chunk) owns reservation land in Woodbury County.
The county is on the western edge of Iowa, with its western border being theMissouri River.
According to theU.S. Census Bureau, the county has a total area of 878 square miles (2,270 km2), of which 873 square miles (2,260 km2) is land and 4.9 square miles (13 km2) (0.6%) is water.[5] It is the third-largest county by area in Iowa.
As of the2020 census, the county had a population of 105,941 and a population density of120.9/sq mi (46.7/km2). The housing stock included 42,701 units, 39,904 of which were occupied.[13]
The median age was 35.8 years; 26.0% of residents were under the age of 18 and 15.4% of residents were 65 years of age or older. For every 100 females there were 99.2 males, and for every 100 females age 18 and over there were 97.5 males age 18 and over.[13]
83.9% of residents lived in urban areas, while 16.1% lived in rural areas.[15]
There were 39,904 households, of which 32.9% had children under the age of 18 living in them. Of all households, 44.7% were married-couple households, 20.2% were households with a male householder and no spouse or partner present, and 26.9% were households with a female householder and no spouse or partner present. About 28.8% of all households were made up of individuals and 11.9% had someone living alone who was 65 years of age or older.[13]
Among the 42,701 housing units, 6.6% were vacant. Of the occupied units, 64.9% were owner-occupied and 35.1% were renter-occupied. The homeowner vacancy rate was 1.3% and the rental vacancy rate was 7.6%.[13]
The 2010 census recorded a population of 102,172 in the county, with a population density of117.1/sq mi (45.2/km2). There were 41,454 housing units, of which 39,052 were occupied.[17]
As of thecensus[18] of 2000, there were 103,877 people, 39,151 households, and 26,426 families residing in the county. The population density was 119 inhabitants per square mile (46/km2). There were 41,394 housing units at an average density of 47 per square mile (18/km2). The racial makeup of the county was 87.48%White, 2.02%Black orAfrican American, 1.69%Native American, 2.41%Asian, 0.04%Pacific Islander, 4.37% from other races, and 1.99% from two or more races. 9.11% of the population wereHispanic orLatino of any race.
Of the 39,151 households, 34.00% had children under the age of 18 living with them, 51.90% were married couples living together, 11.30% had a female householder with no husband present, and 32.50% were non-families. 26.60% of households were one person and 11.20% were one person aged 65 or older. The average household size was 2.58 and the average family size was 3.13.
The age distribution was 27.30% under the age of 18, 10.20% from 18 to 24, 28.30% from 25 to 44, 20.80% from 45 to 64, and 13.40% 65 or older. The median age was 34 years. For every 100 females, there were 96.10 males. For every 100 females age 18 and over, there were 92.80 males.
The median household income was $38,509 and the median family income was $46,499. Males had a median income of $31,664 versus $22,599 for females. The per capita income for the county was $18,771. About 7.20% of families and 10.30% of the population were below thepoverty line, including 13.60% of those under age 18 and 7.40% of those age 65 or over.
For much of the second half of the 20th century, Woodbury County tilted Republican, albeit not as overwhelmingly as most of western Iowa. Between 1988 and 2012 Woodbury County was the quintessential swing county in Iowa. No candidate won it by more than 3.5% over that quarter-century. This was the only county in Iowa thatBarack Obama won in 2012 that he failed to carry in 2008. However, in 2016, Woodbury County, like Iowa as a whole, swung over dramatically toDonald Trump, who carried it by a 19 percent margin, the largest margin of victory sinceLyndon Johnson's landslide election in 1964.
United States presidential election results for Woodbury County, Iowa[19]