County Formation. When Illinois became a state in 1818, the area that is now Marshall county was part of Bond and Clark counties. As more counties were formed, the area became part of Pike, Sangamon, Putnam, and LaSalle counties. Marshall county was established in 1839 from Putnam county.
Topeka is an incorporated town in Mason County, Illinois, United States. The population was 90 at the 2000 census. Topeka is located at 40Â°19â²48â³N 89Â°55â²52â³Wï»¿ / ï»¿40.33000Â°N 89.93111Â°Wï»¿ / 40.33000; -89.93111 (40.329960, -89.931034). According to the 2010 census, Topeka has a total area of 0.14 square miles (0.36 km 2), all land.
The highest monthly average temperature in Topeka for July is 79 degrees. The lowest monthly average temperature in Topeka for December is 31 degrees. The most monthly precipitation in Topeka occurs in June with 5.4 inches. The air quality index in Topeka is 27% better than the national average. The pollution index in Topeka is 77% better than the national average.