US National Archives
Nara: Teaching With Documents: Glidden's Patent Application for Barbed Wire
This article from the National Archives and Records Administration (NARA), describes how barbed wire was important for ranchers in the West in the 1800s and how Joseph Glidden improved the original patent for barbed wire.
PBS
Pbs the West: Joseph Farwell Glidden
Information about the Illinois farmer who improved fencing the plains that led to the demise of open-range cattle ranching. Glidden is credited with the invention of barbed wire.