The earliest Hugos for which I have been able to find full voting numbers are the 1980 Hugo awards given at Noreascon Two. The details were release in December 1980, some months after the convention was over, and are available in a seven-page PDF here (the last two pages of the scan are in the wrong order).
563 nomination votes were received, which was a record at the time but was exceeded four times in the rest of the 1980s. (See George Flynn's records.) Nominations seem to have then dipped again until the recent rise.
The 1788 votes for the final ballot were also a record at the time, and a record which as far as I can tell stood for over thirty years until 2100 voted for the 2011 Hugos at Renovation.
(Incidentally I find it fascinating that participation in Site Selection was well ahead of the Hugos for most of the 1980s and 1990s, peaking at 2509 in 1992, a tight-fought campaign between the eventual 1995 Intersection in Glasgow and a rival bid from Atlanta.)
The closest result in 1980 was for the Gandalf Grand Master Award for life achievement in fantasy writing, won by Ray Bradbury by a single vote, mailed in late from England, ahead of Anne McCaffrey, 747 to 746. This was the seventh and second-last Gandalf Award; the other winners had been J.R.R. Tolkien (posthumously in 1974), Fritz Leiber (1975), L. Sprague de Camp (1976), Andre Norton (1977), Poul Anderson (1978) and Ursula K. Le Guin (1979). There had also been two Gandalf Awards for Book-Length Fantasy, going to The Silmarillion in 1978 and The White Dragon in 1979. Noreascon Two, however, decided not to put the Book-Length Fantasy category on the ballot in 1980, and the Business Meeting decided to drop the Gandalf Award altogether, so the last winner was C. L. Moore in 1981.
While I accept that both Bradbury and McCaffrey straddled the blurry sf/fantasy divide, I'd have placed the most famous works of both writers on the sf side and find myself wondering why they were considered appropriate for life achievement in fantasy writing. A more obvious candidate for me would have been Roger Zelazny, who beat McCaffrey for second place (narrowly, by 12 votes) on transfers from Bradbury and Jack Vance. McCaffrey came third, Vance fourth, Marion Zimmer Bradley fifth and Patricia McKillip (then aged 32, thus surely a little premature for a lifetime achievement award) sixth. Zelazny had had by far the most nominations (91 to 60 each for Bradbury and McCaffrey). Michael Moorcock, with 42 nominations, declined a place on the ballot, thus bringing on both Bradley and McKillip who had 34. Next after that cutoff, a long way behind, was Katherine Kurtz on 22.
The next closest result was the Hugo for Best Novel, which went to Arthur C. Clarke's The Fountains of Paradise by 19 votes, 671 to 652 for John Varley's Titan. I have to feel that the Hugo voters got it right (even if Jo Walton disagrees – see also excellent commentsThe Fountains of Paradise won the Nebula as well that year, but was only third in the Locus poll behind Titan (which won) and Frederik Pohl's Jem. It was also nominated for the 1979 BSFA Award but lost to J.G. Ballard's The Unlimited Dream Company.
Titan took second place in the Hugo, Jem picked up transfers from the two front-runners to overtake McKillip's Harpist in the Wind for third, Harpist in the Wind then took fourth place and Thomas Disch's On Wings of Song fifth. Titan had been well ahead in nominations, 146 to 91 for the Clarke; both Orson Scott Card's A Planet Called Treason and Kate Wilhelm's Juniper Time (like Titan, Jem, and On Wings of Song, also a Nebula nominee) missed the cut by 5 nominations, 46 to 51 for Harpist in the Wind.
For Best Novella, Barry B. Longyear's "Enemy Mine" won a clear victory, outpolling "Songhouse", by Orson Scott Card and "The Moon Goddess and the Son", by Donald Kingsbury while both were still in the race, by 570 to 369 and 180 respectively. Longyear's campaigning attracted the scorn of Dave Langford at the time, but "Enemy Mine" has certainly proved to be the finalist with the most staying power; it also won the Nebula and Locus Awards that year. Second place went to "Songhouse", third to "The Moon Goddess and the Son", by Donald Kingsbury, fourth to "Ker-Plop", by Ted Reynolds and fifth to "The Battle of the Abaco Reefs", by Hilbert Schenck. That was also the pattern of nominations, except that "Ker-Plop" barely made it, by 39 to 36 for Frederik Pohl's "Mars Masked", which like "The Battle of the Abaco Reefs" was also a Nebula nominee.
This was a year when three out of four fiction categories went to the same works for both Hugo and Nebula. "Sandkings", by a now-forgotten writer called George R.R. Martin, won Best Novelette by 638 votes to 458 for "Homecoming" by Barry B. Longyear. "Options" by John Varley, which had the third highest number of first preferences in the first round and second highest in the second round, was then outpolled by "The Locusts" by Larry Niven and Steven Barnes for third place and by "Fireflood" by Vonda N. McIntyre for fourth place before winning fifth place ahead of "Palely Loitering" by Christopher Priest. "Sandkings" is indeed a memorably creepy story and a worthy winner, though I haven't read any of the others so can't judge how the competition matched up (only "Options" was also on the Nebula ballot). I don't know why there were six finalists on the ballot; the published figures show "Fireflood" fifth with 40 nominations and "Homecoming" sixth with 39, so perhaps there was a recount after the ballot had been published. "Out There Where The Big Ships Go", by Richard Cowper, missed the cutoff with only 33 nominations. Some way behind, in tenth place with 27, is "Galatea Galante, The Perfect Popsy", by Alfred Bester, which I remember boggling over as a teenager but I suspect would not stand up to rereading now.
Martin (I do wonder what heppened to him?) won also for Best Short Story with "The Way of Cross and Dragon" which got 569 votes to 456 for "Unaccompanied Sonata" by Orson Scott Card. "Can These Bones Live?" by Ted Reynolds came third, "giANTS" by Edward Bryant (which won the Nebula) came fourth and "Daisy, in the Sun", an early story by Connie Willis, came fifth. "Can These Bones Live?" actually received the most nominations, 56 to 48 for "The Way of Cross and Dragon"; "Daisy, in the Sun" had the fifth highest number of nominations at 27, closely followed by Spider Robinson's "God is an Iron" on 26, Somtow Sucharitkul's "The Thirteenth Utopia" on 25 and Tanith Lee's "Red as Blood" on 23. As has been the case more recently, the Best Short Story category saw a particularly dispersed pattern of nomination.
This was the first time that the Hugo for Best Non-Fiction was awarded. It went to what we now know as the first edition of The Science Fiction Encyclopedia, by Peter Nicholls, by 639 votes to 563 for the first volume of Isaac Asimov's memoirs, In Memory Yet Green. Asimov took second place convincingly, Barlowe's Guide to Extraterrestrials by Wayne Barlowe and Ian Summers took third, and Wonderworks by Michael Whelan fought off a challenge for fourth place from The Language of the Night by Ursula K. Le Guin with Susan Wood. In nominations, the top two places were the same, The Science Fiction Encyclopedia top with 121 and Asimov next with 97, followed by Le Guin and then Barlowe with Wonderworks a long way behind on 23, only three votes ahead of both Lester Del Rey's The World of Science Fiction: 1926-1976: The History of a Subculture and A Reader's Guide to Science Fiction by Baird Searles, Martin Last, Beth Meacham and Michael Franklin which both got 20.
Best Professional Editor went to George H. Scithers, in the middle of his five-year tenure as editor of Isaac Asimov's Science Fiction Magazine, by 676 votes to 644 for Edward L. Ferman, long-time editor and publisher of The Magazine of Fantasy and Science Fiction. Ferman took second place; third went to Ben Bova, in the middle of his four years at Omni, and Stanley Schmidt, relatively recently appointed editor of Analog Science Fiction and Fact in succession to Ben Bova, came from behind to take fourth place from Jim Baen, presumably nominated for his work with Tom Doherty at Ace, and thus the only long form rather than short form editor on the ballot. Ferman had been slightly ahead of Scithers in nominations, 183 to 171; Terry Carr missed the cutoff by a significant margin, 86 to Schmidt's 111.
Michael Whelan scored a solid victory for Best Professional Artist by 644 votes to 332 for Vincent di Fate and 284 for Boris Vallejo. Di Fate came second; Stephen Fabian benefited from transfers to take third place from Vallejo, who however came fourth; Paul Lehr came fifth. Whelan was far ahead on nominations as well, with 151 to 98 for Di Fate. Kelly Freas, with 36, was some way behind Vallejo's 48.
The results for Best Dramatic Presentation include a couple of "What were they thinking?" moments. Not as far as the winner goes – Alien is by most metrics not just the best known sf film from 1979, but the best known film of any genre from that year. It won by a good margin, 881 to 588, over a film I had not even heard of – Time After Time, starring Malcolm McDowell as H.G. Wells, David Warner as Jack the Ripper, and Mary Steenburgen as McDowell's twentieth-century love interest. The first "What were they thinking?" moment is that this completely forgotten film, which came second overall, beat Star Trek: The Motion Picture, which came third, and The Muppet Movie, which came fourth. This was also a rare pre-2015 success for No Award, which beat Disney's The Black Hole for fifth place. (The second "What were they thinking?" moment applies to Disney for making The Black Hole at all.) Alien was way ahead in nominations with 234 for 196 for Star Trek: The Motion Picture, followed by Time After Time, The Black Hole, The Lathe of Heaven (ruled ineligible until the following year, when it came second to The Empire Strikes Back), and The Muppet Movie well in the rear with 28; the next in line was Moonraker with 20.
Those were the days when Locus, edited by Charles N. Brown was eligible for Best Fanzine, and won by 511 to 330 for Science Fiction Review, edited by Richard E. Geis; between them they won every award in this category from 1976 to 1983. Science Fiction Review came second; File 770, which is a finalist again this year and is still edited by Mike Glyer, fought off a strong challenge for third place from Janus, edited by Janice Bogstad and Jeanne Gomoll; Janus came fourth and Thrust, edited by Doug Fratz, fifth. Science Fiction Review was well ahead on nominations, with 84 to 68 for Locus. Thrust brought up the rear with 31; Jeff Duntemann's PyroTechnics got 25.
Bob Shaw, who by 1980 had published 15 sf novels and a short story collection, won Best Fan Writer handily enough by 391 to 325 for Richard E. Geis. Geis came a very convincing second, and third, fourth and fifth places went to Mike Glyer (again, a finalist this year), Dave Langford and Arthur D. Hlavaty respectively. The nominations had been rather different, with Geis's 60 far ahead of 20 for Langford, 18 for Hlavaty and Shaw and 15 for Mike Glyer. George M. Ewing, Mike Glicksohn and Jeanne Gomoll were all two votes adrift on 13.
Alexis Gilliland scored the first of four victories in Best Fan Artist by 449 votes to 280 for Victoria Poyser, who won the following two years. She seems to have been a bit transfer-repellent, losing second place to William Rotsler and third place – by only two votes – to Joan Hanke-Woods. Stu Shiffman came fifth and Jeanne Gomoll sixth. Gilliland was also way ahead on nominations with 99 to Poyser's 37. Rotsler and Shiffman tied for fifth place in nominations with 25, Grant Canfield being not far behind with 22.
Finally (aren't you glad?) the John W. Campbell Award went to Barry B. Longyear, by a stunning margin: 644 on the first count, to 177 for Somtow Sucharitkul, 157 for Diane Duane, 104 for Lynn Abbey, 54 for Karen G. Jollie and 42 for Alan Ryan (who took the other places in that order) with 77 for No Award. Longyear turned out to be a one-hit wonder; Sucharitkul and Duane remain visible and active; I don't think I'd heard of Abbey or Ryan before, but both have real enough subsequent records; Karen G. Jollie published two stories in 1978 and one in 1980, but has otherwise made her career as an artist. Longyear was also far ahead on nominations, with 110 to 51 for Sucharitkul, 32 for Duane, 30 for the ineligible Connie Willis and 14 each for Abbey, Jollie and Ryan. Linda E. Bushyager missed by one vote, with 13, but as she had had a story published in 1968 she would not have been eligible in any case.
It’s a shame that we don’t have more of this early data available – presumably some of it is lurking in people’s attics – but it’s interesting that the one year we have featured unusually high turnout for the time, and allegations of campaigning. Apart from 1980, the only twentieth-century nomination statistics I’ve seen are from 1984, 1994 and 1998; since 2000 the records seem fairly complete though. Let’s hope to do a better job of keeping track for the analysts of the 2040s.