Harrisburg is a census-designated place in, and the county seat of, Banner County, Nebraska, United States. The population was 100 at the 2010 census. Harrisburg, and all of Banner County, were originally part of Cheyenne County and began with a homestead in 1884. A settlement, at first called Randall and then Centropolis, developed around this and …Harrisburg is a census-designated place in, and the county seat of, Banner County, Nebraska, United States. The population was 100 at the 2010 census. Harrisburg, and all of Banner County, were originally part of Cheyenne County and began with a homestead in 1884. A settlement, at first called Randall and then Centropolis, developed around this and neighboring homesteads. In November, 1888, Cheyenne County subdivided into five counties, and the settlement was included in the territory which became Banner County. Its county seat was originally located at Ashford, a few miles northeast. However, in 1889 Charles Schooley, a settler, donated part of his land for the development of a formal town. A migrant being from Harrisburg, Pennsylvania caused the name to be selected.