[2] In the Nebraska license plate system, Richardson County is represented by the prefix 19 (it had the nineteenth-largest number of vehicles registered in the county when the license plate system was established in 1922).

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.

This tornado measured F4 on the Fujita scale, and had a damage path 800 yards (730 m) wide and 100 miles (160 km) long.

[5] In the summer of 1966, Braniff Airlines Flight 250 crashed near Falls City due to bad weather, killing all 42 on board.

[6] The BAC One-Eleven aircraft was on the Kansas City to Omaha leg of a multi-stop flight from New Orleans to Minneapolis on Saturday night, August 6, 1966.

The county's terrain consists of rolling hills, sloped to the southeast, cut by numerous drainages.

In only one national election since 1936 has the county selected the Democratic Party candidate (as of 2024).