カンザス・ネブラスカ法
The Nebraska Territory, including this county, was opened for settlement through the Kansas–Nebraska Act on May 30, 1854. Richardson County was created that same year and reorganized in 1855 by the first territorial legislature. It was named after William A. Richardson, a US Representative from the state of Illinois who had sponsored the Kansas-Nebraska Act; subsequently, in 1858, Richardson was appointed governor of the Nebraska Territory.