Resident Population in Morgan County, IL was 32.61800 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Morgan County, IL reached a record high of 37.80000 in January of 1978 and a record low of 32.61800 in January of 2024. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Morgan County, IL - last updated from the United States Federal Reserve on April of 2026.