Johnson County, Iowa
Founding: 1838 (declared in 1837) Parent counties: Cook, Dubuque, Muscatine, and unorganized territory Namesake: Richard Johnson, U.S. vice president Seat: Napoleon (1838–1839); Iowa City (1839–) Land area: 614 square miles Population (2020): 152,854 Population (historic): 4,472 (1850); 24,898 (1870); 23,082 (1890); 25,914 (1910); 30,276 (1930) Periods of population growth: pre-1850–1880; 1890–2020 Subdivisions: 11 cities; one CDP; 20 townships Pre-1940 residences (estimated): 7,349 (11.1%) Pre-1940 housing survival rate: 69.1% Pre-1860 housing survival rate (1940): 5.3% Farm housing in disrepair (1950): 2.9% Nonfarm housing in disrepair (1950): 2.7% Average farmhouse value (1930): $2,561 Average outbuilding value (1930): $3,078 Average farmhouse size (1940): 6.7 rooms Number of farms (1920): 2,625 Average farm size (1920): 122.1 acres Sources of settlement: Czechosl...