Harnett County, NC neighbors Johnston near Lillington Metropolitan Centre giving us a 2020 estimated population estimate standing at 122,640 making it the 21st most populous county located hereabouts. Its county seat is Lillington although other cities include Angier & Dunn - Lillington itself equates out to Harnett's largest town aside from acknowledged country seat. This area had been formed from Cumberland and Johnston Counties back in 1855 when local residents petitioned for new administrative boundaries - posthumously named after American Revolutionary War soldier Cornelius Harnett whose successful career within continental congress continued late 18th century onward.