DuPage County, Illinois

Founding: 1839
Parent county: Cook

Namesake: The DuPage River
Seat: Naperville (1839–1867); Wheaton (1867–)

Land area: 327 square miles

Population (2020): 932,877

Population (historic): 3,535 (1840); 14,701 (1860); 19,161 (1880); 28,196 (1900); 91,998 (1930)

Periods of population growth: pre-1840–2020

Subdivisions: Seven cities; 20 villages; nine townships

Pre-1940 residences (estimated): 19,432 (5.4%)
Pre-1940 housing survival rate: 76.3%
Pre-1860 housing survival rate (1940): 19.8%

Farm housing in disrepair (1950): 4.8%

Nonfarm housing in disrepair (1950): 2%

Average farmhouse value (1930): $3,520
Average outbuilding value (1930): $3,537

Average farmhouse size (1940): 6.8 rooms
Number of farms (1920): 1,756
Average farm size (1920): 88.6 acres
Sources of settlement: Germany, New York, Pennsylvania, and England
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Naperville (ex-seat)

Namesake: Joseph Naper, owner of the city site

Founding: circa 1832 (founding); 1836 (post office); 1857 (incorporation)

Population (2020): 149,540

Population (historic): 1,713 (1870); 2,216 (1890); 3,449 (1910); 5,118 (1930)

Periods of population growth: pre-1870–2020
Pre-1940 residences (estimated): 1,268 (2.3%)
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Wheaton

Namesake: Warren Wheaton, owner of the city site

Founding: 1852 (post office); 1853 (platting); 1859 (incorporation)

Population (2020): 53,970

Population (historic): 645 (1860); 1,160 (1880); 2,345 (1900); 7,258 (1930)

Periods of population growth: 1853–2000; 2010s
Pre-1940 residences (estimated): 1,594 (7.9%)
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Outstanding Buildings

1. Heinrich Harmening Farm (c. 1870). 258 Lake Street. Bloomingdale. Italianate.
2. House (c. 1910). 8521 Bailey Road. Downer's Grove. Classical Revival.
3. Maple Terrace / Truman Van Norman House (1901). 1520 Loomis Street. Lisle. Classical Revival/Queen Anne.
4. Jacob Snibley Farm (1852). 608 Olesen Road. Lisle. Greek Revival. Razed.
5. Moses Stacy Tavern (1846). 557 Geneva Road. Milton. Greek Revival.
6. George Baker House (1847). 500 Taylor Road. Milton. Greek Revival.
7. James Wright House (c. 1855/1910). 1025 Aurora Avenue. Naperville. Italianate/Classical Revival.
8. Pine Craig / George Martin House (1883). 523 South Webster Street. Naperville. Italianate.
9. Daniel Dunham House (c. 1890). 141 Army Trail Road. Wayne. Queen Anne.
10. George Reed House (c. 1850). St. Charles Road and Prince Crossing Road. Wayne. Greek Revival.
11. Francis Kline Farm (c. 1885). 600 County Farm Road. Winfield. Eastlake.
12. Frederick Graue House (1858–1859). 3800 York Road. York. Italianate.
13. Graue Mill (1852). 3800 York Road. York. Greek Revival.

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