Great article! My only feedback on the article is that you cite sources (maybe I missed it).
I find the Western Union and Hayes espionage story emotionally appealing but I couldn't find any serious sources with a quick Google search. The Rutherford B. Hayes Wikipedia article mentions neither Western Union or any sort of spying/espionage.
This is explored in Tim Wu's book, which I strongly recommend reading. "The Master Switch: The Rise and Fall of Information Empires": http://amzn.to/2cjtFDH
I find the Western Union and Hayes espionage story emotionally appealing but I couldn't find any serious sources with a quick Google search. The Rutherford B. Hayes Wikipedia article mentions neither Western Union or any sort of spying/espionage.