I’ve lately become interested in coverage of Election Day vote totals in the past. Specifically, how did newspapers or broadcasters get vote totals in the past and how exactly did they use the results to “call” elections? (For example, Lincoln knew before midnight of Election Day in 1860 he’d been elected–how on earth did they know so early?) Were there any cases where it took days or even weeks to know the final results? And why did broadcasters in the past often be several hours apart calling the same election?
The length of time between election day and the day the Electoral College members meet was set to be more than a month in the beginning because it did take that much time to get results in.
By 1860, though, the telegraph was near universal in every town and city, and followed along the railroad lines. Elections were a very big deal. They were also simpler to count, since they didn’t have the multiplicity of referendums and local elections were usually scheduled on different days. So people were standing by everywhere to get results to the telegraphers as fast as possible.
All they could know was the raw vote. The practice of using exit polls and statistically matching them to key precincts is a quite recent innovation. Today there’s a central bureau that all the news organizations draw on - although they still make individual in-house projections so the calls aren’t always synchronized - but in the beginning they had their own pollsters for a competitive advantage until they realized how much money that wasted.
To expand on what Exapno Mapcase said, by 1860 there was a national telegraphic infrastructure, plus well organized wire services that provided results to the newspapers. The political parties could also lease telegraph lines for private communication. For example, the morning after the election, the November 7, 1860 Cleveland Morning News already declared Lincoln elected and had pretty complete election results: “We give below the vote of Cleveland City and Cuyahoga county in detail, and of Ohio and all other states, so far as reported by telegraph up to the hour of going to press.”
Later developments included audio transmissions, and in some cases local telephone companies set up party lines to report results to their subscribers, for example Distributing National Election Returns by Telephone in the November 9, 1912 Telephony.
Around this time the big Navy radio stations started sending out election results, but this was by Morse code, so the audiences were limited. The first audio radio broadcast of election returns occurred in November, 1916: Election Returns Flashed by Radio to 7,000 Amteurs reviews Lee DeForest’s broadcast by his station in New York City. This was a close election, and the station signed off before the California returns were in, so it incorrectly said that Hughes had defeated Wilson.