Whiteside County is named after General Samuel Whiteside who was an officer in the Ware of 1812 and the Black Hawk War. The county is the birthplace of President Ronald Reagan (Tampico). According to the 2017 Census of Agriculture, there were 959 farms in Whiteside County, spanning 370,763 acres, with an average farm size of 387 acres. The population of Whiteside County was 58,498 (based on 2010 census). Its temperatures range from 10°F during January to 85°F during July. Average monthly precipitation ranges from 1.51" during February to 4.69" during August. If you're looking for land for sale in Whiteside County, IL, check out Land Pro LLC's current listings below. If there are no current listings in Piatt County, take a look at land for sale in neighboring Bureau County, Henry County, Lee County, and Ogle County. You can also view all the Illinois land offered for sale by Land Pro LLC.