Monroe County is a county located in the U.S. state of Illinois. According to the 2020 census, it had a population of 34,962. Its county seat and largest city is Waterloo.
Monroe County is included in the St. Louis, MO-IL Metropolitan Statistical... Wikipedia
Population: 35,033 (2022)
Area: 398 mi²
Congressional district: 12th
Largest city: Waterloo
Named for: James Monroe
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