Warren County
County in Illinois
Warren County is a county in the U.S. state of Illinois. According to the 2020 census, it had a population of 16,835. Its county seat is Monmouth. Wikipedia
Population: 16,354 (2022)
Cities: Monmouth, Roseville, Little York, and more
County seat: Monmouth
Area: 543 mi²
Named for: Joseph Warren
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