@skribe Works became eligible for Retro Hugos at 50, 75, or 100 years after their publication date if there were no Hugo awards nominated for their publication year (https://en.wikipedia.org/wiki/Hugo_Award#Retro-Hugos).
As LOTR was published between 1954 and 1955 (https://en.wikipedia.org/wiki/The_Lord_of_the_Rings), that would have made the individual books eligible in 2004/2005, but they wouldn't have been eligible again until 2029/2030 or 2054/2055.
Retro Hugos started in 1996 and were optional; it was up to that year's Hugo committee as to whether or not they'd award them.
Noreascon 4 (2004's Worldcon) did award Retro Hugos for 1954; neither TFotR nor TTT were nominated (https://www.thehugoawards.org/hugo-history/1954-retro-hugo-awards/). I can't speak to why (that was before I started paying attention to the Hugos); it's possible that they were nominated, but not in sufficient numbers to make the final ballot.
The Hugo award was awarded in 1955, so TRotK would not have been eligible for a Retro Hugo. Nominations for the 1955 Hugos are not listed on the award's official site, so I don't know if TRotK was nominated that year (https://www.thehugoawards.org/hugo-history/1955-hugo-awards/).
This past year the Hugo awards were officially removed from the WSFS constitution, so no further Retro Hugos will be awarded.
#Worldcon #HugoAward #LordOfTheRings #LOTR