Marshall County, Illinois

Marshall County
Lacon Bridge in the county seat
Lacon Bridge in the county seat
Map of Illinois highlighting Marshall County
Location within the U.S. state of Illinois
Map of the United States highlighting Illinois
Illinois's location within the U.S.
Coordinates: 41°02′N 89°20′W / 41.03°N 89.34°W / 41.03; -89.34
Country United States
State Illinois
FoundedJanuary 19, 1839
Named forJohn Marshall
SeatLacon
Largest cityHenry
Area
 • Total399 sq mi (1,030 km2)
 • Land387 sq mi (1,000 km2)
 • Water12 sq mi (30 km2)  2.9%
Population
 (2020)
 • Total11,742
 • Density29/sq mi (11/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional district16th
Websitewww.marshallcountyillinois.com

Marshall County is a county located in the U.S. state of Illinois. According to the 2020 census, it had a population of 11,742.[1] Its county seat is Lacon.[2]

Marshall County is part of the Peoria, IL Metropolitan Statistical Area.

  1. ^ "Marshall County, Illinois". United States Census Bureau. Retrieved June 10, 2023.
  2. ^ "Find a County". National Association of Counties. Retrieved June 7, 2011.