Winthrop is a city in Buchanan County, Iowa, United States. The population was 823 at the time of the 2020 census. History Winthrop was platted in 1857. Geography Winthrop is located at (42.472419, -91.735713). According to the United States Census Bureau, the city has a total area of , all land. Winthrop is located north of U.S. Route 20. Demographics 2010 census As of the census of 2010, there were 850 people, 346 households, and 228 families living in the city. The population density was . There were 357 housing units at an average density of . The racial makeup of the city was 98.7% White, 0.1% Native American, 0.2% Asian, 0.1% from other races, and 0.8% from two or more races. Hispanic or Latino of any race were 0.4% of the population. There were 346 households, of which 31.8% had children under the age of 18 living with them, 52.3% were married couples living together, 9.0% had a female householder with no husband present, 4.6% had a male householder with no wife present, and 34.1% were non-families. 28.9% of all households were made up of individuals, and 14.5% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 3.00. The median age in the city was 38.5 years. 27.5% of residents were under the age of 18; 5.7% were between the ages of 18 and 24; 24.2% were from 25 to 44; 26.7% were from 45 to 64; and 16% were 65 years of age or older. The gender makeup of the city was 50.0% male and 50.0% female. 2000 census As of the census of 2000, there were 772 people, 327 households, and 206 families living in the city. The population density was . There were 341 housing units at an average density of . The racial makeup of the city was 99.09% White, 0.39% Native American, 0.26% from other races, and 0.26% from two or more races. Hispanic or Latino of any race were 0.39% of the population. There were 327 households, out of which 30.6% had children under the age of 18 living with them, 52.0% were married couples living together, 8.3% had a female householder with no husband present, and 37.0% were non-families. 33.9% of all households were made up of individuals, and 17.7% had someone living alone who was 65