Yes, it's yet another book poll!

Incidentally, the best-selling book in the USA in 1915 was The Turmoil, by Booth Tarkington, which has been almost completely forgotten. In 1965 it was The Source, which does seem to have had more staying power (it also topped the NYT Best Sellers list from July 1965 until the end of the year). I would like to bring in other countries’ best-seller lists for comparison, but can’t find any online.