A historian's study of that issue is much to be desired. Larry's A Patriot's History of the United States, good as it is, omits any mention of the telegraph that I was able to find. He said that the book had to be ruthlessly cut down to fit within the covers of what his publisher was willing to print . . .IMHO that is like omitting any mention of radio and TV in a discussion of politics in the 20th Century.
I don’t have it in front of me, but I’m pretty sure we discussed the telegraph, just not in the context of news bias. And no, I don’t have a problem with that. Most of the history of journalism I’ve researched pretty much concludes that there were multiple factors, including the “managerial revolution,” the demise of the Dem-dominated partisan press, the demands of facts about the war, and others, all EQUAL to the telegraph, that seems to me to make the omission in this context entirely justifiable.