Montgomery County, Illinois

Founding: 1821
Parent counties: Bond and Madison

Namesake: Richard Montgomery, Continental Army general
Seat: Hamilton (1821–1823); Hillsboro (1823–)

Land area: 704 square miles

Population (2020): 28,020

Population (historic): 2,953 (1830); 13,979 (1860); 28,078 (1880); 30,836 (1900); 35,278 (1930)

Periods of population growth: pre-1830–1920; 1970s

Subdivisions: Five cities; 15 villages; 18 townships

Pre-1940 residences (estimated): 3,283 (25%)
Pre-1940 housing survival rate: 45.1%
Pre-1860 housing survival rate (1940): 7.7%

Farm housing in disrepair (1950): 3.9%

Nonfarm housing in disrepair (1950): 8.5%

Average farmhouse value (1930): $1,313
Average outbuilding value (1930): $1,083

Average farmhouse size (1940): 5.9 rooms
Number of farms (1920): 3,037
Average farm size (1920): 117.8 acres
Sources of settlement: Ohio, Germany, Kentucky, Pennsylvania, Missouri, North Carolina, Tennessee, and Ireland
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Hillsboro

Namesake: A descriptive name

Founding: 1823 (platting); 1823 (post office); 1855 (incorporation)

Population (2020): 5,902

Population (historic): 853 (1860); 1,803 (1880); 1,937 (1900); 4,435 (1930)

Periods of population growth: pre-1860; 1900–1920; 1930s; 1950–1980; 2000s
Pre-1940 residences (estimated): 385 (21.8%)
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Outstanding Buildings

1. Lewis Thomas Farm (1863–1865/1888). 34378 East Frontage Road. Bois d'Arc. Romanesque/Classical Revival.
2. Charles Jenkins House (c. 1865). 9032 State Route 127. Butler Grove. Italianate.
3. Benjamin Ware House (c. 1830). 9138 Ware's Grove Road. Butler Grove. Razed.
4. Amos Sawyer House (c. 1875). 9250 State Route 127. Hillsboro. Italianate.

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