Here are the telegraph men waiting on President Lincoln, played (superbly) by Daniel Day Lewis. I wondered as I watched this how busy the lines really were.
Turns out, all-night press traffic by telegraph was big business by 1860. Almost every US daily had signed up to the Associated Press news feed, now 10 years old. The appetite for political news even before the Civil War was so voracious that by special arrangement the New York Herald got the transcript of a speech by Henry Clay hours after he spoke it in Kentucky, clear back in 1847. It cost $500, which they were happy to pay.* I notice that Augustus Melmotte, Trollope’s villain financier in the early ‘seventies, stayed in touch with San Francisco and Salt Lake City as though they were suburbs of London.**
*George B. Prescott, History, Theory and Practice of the Electric Telegraph, 1860, p. 385 ff.
**The Way We Live Now, Chapter 10, first paragraph. This is page 47 in the 1875 Harper edition.