'Henderson County, IL' definitions:

Henderson -- U.S. County in Illinois

From: Gazetteer 2000
Name :
Henderson -- U.S. County in Illinois
Population (2000) :
8213
Housing Units (2000) :
4126
Land area (2000) :
378.811971 sq. miles (981.118459 sq. km)
Water area (2000) :
16.312172 sq. miles (42.248329 sq. km)
Total area (2000) :
395.124143 sq. miles (1023.366788 sq. km)
Located within :
Illinois (IL), FIPS 17
Location :
40.833378 N, 90.946340 W