The best site for reading about the history of chess in Nebraska is http://nsca.nechess.com/history/jjirous.htm. Jim Jirousek spent untold hours in its construction over the years.
The Gambit, the Nebraska State Chess Association magazine, contains historical articles. Several Nebraskan players own bound collections of the Gambit spanning several decades, as well as similar collections of the Ohman Memorial Newsletter.
The Nebraska State Historical Society library in downtown Lincoln (1500 R Street) holds the archives for Nebraska State Chess Association. This includes past copies of the Gambit and other state chess publications as well as numerous historical documents relating to Nebraska chess. See http://www.nebraskahistory.org/lib-arch/
Recently Kent Nelson has written and published a book about the life and games of Anton Sildmets, a mainstay of the Lincoln chess scene and a Nebraska state champion as well as a national correspondence champion. It includes a swath of Lincoln chess history and portraits of Nebraska chess icons. If you're interested in this book, contact Kent at KentNelson@prodigy.net.
Here are a few old photos of Lincoln and Omaha players, including many from the 1969 U.S. Open organized by Hess Baluch: