Falls City is a city in and the county seat of Richardson County, Nebraska, United States. The population was 4,133 at the 2020 census, down fr…Falls City is a city in and the county seat of Richardson County, Nebraska, United States. The population was 4,133 at the 2020 census, down from 4,325 in 2010 and 4,671 in 2000. Falls City was founded in the summer of 1857 by James Lane, John Burbank, J. E. Burbank, and Isaac L. Hamby. The men were all Abolitionists and the city was established as a station on the Underground Railroad on a section referred to as the Lane Trail.