Keokuk County was opened for white settlement in 1843, and the town got its start in 1844 when S.A. James built the first cabin there. Other families began to settle there as well, and in 1844, the town was named by county commissioner Dr. George H. Stone in honor of popular poet Lydia Sigourney. A large oil-painted portrait of Lydia still graces the foyer of the county courthouse.
As of the census of 2010, there were 2,059 people, 878 households, and 537 families living in the city. The population density was. There were 987 housing units at an average density of. The racial makeup of the city was 98.2% White, 0.7% African American, 0.2% Native American, 0.3% Asian, 0.1% from other races, and 0.4% from two or more races. Hispanic or Latino of any race were 0.4% of the population. There were 878 households of which 27.8% had children under the age of 18 living with them, 47.5% were married couplesliving together, 9.5% had a female householder with no husband present, 4.2% had a male householder with no wife present, and 38.8% were non-families. 34.3% of all households were made up of individuals and 18.7% had someone living alone who was 65 years of age or older. The average household size was 2.23 and the average family size was 2.85. The median age in the city was 45.1 years. 22.5% of residents were under the age of 18; 6.6% were between the ages of 18 and 24; 20.8% were from 25 to 44; 24.9% were from 45 to 64; and 25.2% were 65 years of age or older. The gender makeup of the city was 47.0% male and 53.0% female.
2000 census
As of the census of 2000, there were 2,209 people, 903 households, and 567 families living in the city. The population density was 1,016.3 people per square mile. There were 992 housing units at an average density of 456.4 per square mile. The racial makeup of the city was 99.09% White, 0.14% African American, 0.14% Native American, 0.45% Asian, 0.14% from other races, and 0.05% from two or more races. Hispanic or Latino of any race were 0.54% of the population. There were 903 households out of which 29.6% had children under the age of 18 living with them, 51.4% were married couples living together, 9.0% had a female householder with no husband present, and 37.1% were non-families. 33.6% of all households were made up of individuals and 21.5% had someone living alone who was 65 years of age or older. The average household size was 2.29 and the average family size was 2.93. Age spread: 23.9% under the age of 18, 7.9% from 18 to 24, 22.7% from 25 to 44, 18.8% from 45 to 64, and 26.7% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 79.7 males. For every 100 females age 18 and over, there were 75.8 males. The median income for a household in the city was $29,803, and the median income for a family was $43,519. Males had a median income of $29,783 versus $21,078 for females. The per capita income for the city was $17,218. About 8.5% of families and 10.8% of the population were below the poverty line, including 14.0% of those under age 18 and 10.7% of those age 65 or over.
The Sigourney Community School District encompasses nearly a radius, drawing students from smaller surrounding communities. Approximately 700 students are enrolled yearly, with an average of 350 attending elementary and 350 students attending junior/senior high. The average graduating class is 50 students with 80% moving on to college. The school system's mascot is the Sigourney Savage.
