I believe the answer is Barbed Wire.
Befor the inventions of barbed wire, the Cattles are let to roam freely across the plains and the owners are required to pay a lot of cowboys to supervise them so they didn't go missing. Witht he invention of barbed wire, they can keep the cattle in a secure place without supervision.
German Army fought in the western
Athenians were able to vote but they were not true democratic
