Sullivan County
Population
The population of Knox County in 1800 and 1810, at both of which censuses Sullivan County was still a part of the original county, was as follows:
1800 - 2,402 and 28 slaves
1810 - 4,551 and 135 slaves
1820 - 3,498
1830 - 4,630
1840 - 8,315
1850 - 10,141
1860 - 15, 064
1870 - 18,453
1880 - 20,336
1890 - 21,887
1900 - 26,005
Source: A History of Sullivan County, Indiana. Closing of the first century’s history of the county and showing the growth of its people, institutions, industries and wealth. Thomas J. Wolfe, Editor. The Lewis Publishing Company, 1909, page 333-334.