Wabaunsee County was created by the territorial legislature on March 25, 1859. The name used since 1859 is from the Potawatomi "Wah-bon-seh". This means "dawn of day." It was the name of the chief of the Potawatomi Indians. Originally, the county was named Richardson. This was named after William Alexander Richardson, a congressman from Illinois, who introduced the first Kansas and Nebraska Bill in the United States House of Representatives. This made certain Indian lands territories in 1854.