Mason County, Illinois
Lat/Long: 40.2500, -89.8833
The Illinois General Assembly created Mason County out of parts of Menard and Tazewell counties in 1841. Later that year, county voters chose Havana as the county seat.
An Act for the Formation of the County of Mason; An Act Supplemental to “An Act for the Formation of the County of Mason”; The History of Menard and Mason Counties, Illinois (Chicago: O. L. Baskin, 1879), 419.