Ainsworth was platted in 1883 when the railroad was extended to that point. It was named for James E. Ainsworth, a railroad engineer who was instrumental in building the railroad through Brown County. Ainsworth was incorporated as a village in December 1883.
Geography
Ainsworth is located at . According to the United States Census Bureau, the city has a total area of, all land.
As of the census of 2010, there were 1,728 people, 804 households, and 450 families living in the city. The population density was. There were 961 housing units at an average density of. The racial makeup of the city was 97.9% White, 0.1% African American, 0.3% Native American, 0.2% Asian, 0.5% from other races, and 1.0% from two or more races. Hispanic or Latino of any race were 1.2% of the population. There were 804 households, of which 26.2% had children under the age of 18 living with them, 44.0% were married couplesliving together, 7.7% had a female householder with no husband present, 4.2% had a male householder with no wife present, and 44.0% were non-families. 39.9% of all households were made up of individuals, and 21.2% had someone living alone who was 65 years of age or older. The average household size was 2.10 and the average family size was 2.83. The median age in the city was 46.2 years. 23.1% of residents were under the age of 18; 6% were between the ages of 18 and 24; 19.7% were from 25 to 44; 26.5% were from 45 to 64; and 24.6% were 65 years of age or older. The gender makeup of the city was 46.8% male and 53.2% female.
2000 census
As of the census of 2000, there were 1,862 people, 845 households, and 501 families living in the city. The population density was 1,879.5 people per square mile. There were 944 housing units at an average density of 952.9 per square mile. The racial makeup of the city was 98.55% White, 0.21% Native American, 0.38% Asian, 0.05% Pacific Islander, 0.21% from other races, and 0.59% from two or more races. Hispanic or Latino of any race were 0.48% of the population. There were 845 households, out of which 26.3% had children under the age of 18 living with them, 49.9% were married couples living together, 7.7% had a female householder with no husband present, and 40.6% were non-families. 38.0% of all households were made up of individuals, and 21.9% had someone living alone who was 65 years of age or older. The average household size was 2.15 and the average family size was 2.85. In the city, the population was spread out, with 24.2% under the age of 18, 5.5% from 18 to 24, 22.7% from 25 to 44, 21.8% from 45 to 64, and 25.9% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 86.4 males. For every 100 females age 18 and over, there were 81.7 males. As of 2000 the median income for a household in the city was $29,357, and the median income for a family was $38,214. Males had a median income of $26,853 versus $18,750 for females. The per capita income for the city was $16,935. About 7.9% of families and 9.8% of the population were below the poverty line, including 13.0% of those under age 18 and 8.5% of those age 65 or over.