Iroquois County, Illinois

Founding: 1834 (declared in 1833)
Parent county: Unorganized territory

Namesake: The Iroquois River
Seat: Iroquois (1837–1839); Middleport (1839–1865); Watseka (1865–)

Land area: 1,117 square miles

Population (2020): 27,077

Population (historic): 1,695 (1840); 12,325 (1860); 35,451 (1880); 38,014 (1900); 32,913 (1930)

Periods of population growth: pre-1840–1880; 1890s; 1950s; 1990s

Subdivisions: Two cities; 20 villages; 26 townships

National Register listings: Six

Pre-1940 residences (estimated): 4,316 (32%)
Pre-1940 housing survival rate: 55.7%
Pre-1860 housing survival rate (1940): 8.6%

Farm housing in disrepair (1950): 3.3%

Nonfarm housing in disrepair (1950): 4.4%

Average farmhouse value (1930): $2,018
Average outbuilding value (1930): $2,560

Average farmhouse size (1940): 6.9 rooms
Number of farms (1920): 3,953
Average farm size (1920): 162.2 acres
Sources of settlement: Indiana, Ohio, Germany, Canada, New York, Ireland, and Pennsylvania
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Watseka

Namesake: Unclear—perhaps Watseka, Potawatomi woman

Founding: 1859 (platting as South Middleport); 1864 (post office); 1867 (incorporation)

Population (2020): 4,679

Population (historic): 1,551 (1870); 2,017 (1890); 2,476 (1910); 3,144 (1930)

Periods of population growth: pre-1870; 1880–1900; 1910–1980; 1990s
Pre-1940 residences (estimated): 587 (20.5%)
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Outstanding Buildings

1. *Iroquois County Infirmary (1917). 2258 County Farm Road. Belmont. Craftsman/Spanish Revival.
2. *Prairie Dell Meeting House (1870). Road 250 North and North 2550 East. Concord. Italianate.
3. *The Larches / Allen Pinkerton Farm (1873). 1546 Road 600 East. Onarga. Italianate. Razed.
4. *John Smith House (c. 1855). Road 780 East, north of East 1200 North. Onarga. Razed.
5. *Christian Knoche Farm (1864). 273 North 300 East. Ridgeland. Italianate.