Cook County, Illinois

Founding: 1831
Parent county: Putnam

Namesake: Daniel Cook, Illinois politician
Seat: Chicago (1831–)

Land area: 945 square miles

Population (2020): 5,275,541

Population (historic): 10,201 (1840); 144,954 (1860); 607,524 (1880); 1,838,735 (1900); 3,982,123 (1930)

Periods of population growth: pre-1840–1970; 1990s; 2010s

Subdivisions: 23 cities; one town; 111 villages; 29 townships

Pre-1940 residences (estimated): 645,442 (29.3%)
Pre-1940 housing survival rate: 48%
Pre-1860 housing survival rate (1940): 13.4%

Farm housing in disrepair (1950): 4.7%

Nonfarm housing in disrepair (1950): 5.2%

Average farmhouse value (1930): $3,090
Average outbuilding value (1930): $2,939

Average farmhouse size (1940): 6.4 rooms
Number of farms (1920): 5,305
Average farm size (1920): 57.2 acres
Sources of settlement: Germany, Ireland, New York, and England
_________________________________________________________________________________

Chicago

Namesake: The Chicago River

Founding: 1830 (platting); 1831 (post office); 1837 (incorporation)

Population (2020): 2,746,388

Population (historic): 4,470 (1840); 112,172 (1860); 503,185 (1880); 1,698,575 (1900); 3,376,438 (1930)

Periods of population growth: pre-1840–1930; 1940s; 1990s; 2010s
Pre-1940 residences (estimated): 517,151 (42.1%)
_________________________________________________________________________________

View and filter the data. Or see a map.
_________________________________________________________________________________

Outstanding Buildings

1. Noble–Seymour House (1833/1868). 5624 North Newark Avenue. Jefferson. Italianate.
2. St. James Catholic Church (1853–1858). 10600 Archer Avenue. Lemont. Gothic Revival.
3. John Wingert House (1854/1870s). 6231 North Canfield Avenue. Leyden. Italianate.
4. Robert Vial House (1856). 7425 South Wolf Road. Lyons. Italianate.
5. The Grove / Robert Kennicott House (c. 1856). 1421 Milwaukee Avenue. Northfield. Gothic Revival.
6. St. John's Lutheran Church (1874). 4247 183rd Street. Rich. Gothic Revival.
7. St. Peter's Lutheran Church (1863). 202 East Schaumburg Road. Schaumburg. Gothic Revival.
8. Charles Iglehart House (1857/1870s). 11118 South Artesian Avenue. Worth. Italianate.

_________________________________________________________________________________