The Nebraska State Historical Society is a Nebraska state agency, founded in 1878 to "encourage historical research and inquiry, spread historical information ... and to embrace alike aboriginal and modern history." It was designated a state institution in 1883, and upgraded to a state agency in 1994.
The agency's mission statement is: "[to] collect, preserve, and open to all, the histories we share."
More information on the Wikipedia page [1]
The website is [2]