In the summer of 1996, I took a freelance job at the Reader’s Catalog—an ambitious experiment in mail-order bookselling that veteran publisher Jason Epstein had devised at the start of the decade. The catalogue was as big as the proverbial phone book, and it was set up so that readers could easily browse and, should they choose, order one or two or all of what were vaunted to be “the 40,000 best books in print.”

Working on the catalogue, I soon discovered that a lot of what at least I took to be the best books weren’t in fact in print. How come?

Well, the obvious answer was that they didn’t sell—and yet that wasn’t quite right. It’s not that these books didn’t sell, so much as that they didn’t sell enough to meet the demands of the economic models of the book market as it had been reshaped by years of mergers among corporate publishers catering, as corporations must, to shareholders. Books on the backlist that had done well enough over the years were cast aside in favor of the next blockbuster that, aided by the marketing muscle of the emerging superstores, every new book had better aspire to be.

The emergence of the superstore, it should be said, coincided with the emergence of America as “the world’s only superpower.” That may seem an odd connection to make, but in fact the end of the Cold War also took a toll on the traditional backlist. All those books about the wider world that the U.S. previously had to struggle to understand and win over—books by writers like Osip Mandelstam, Anna Seghers, and Marina Tsvetaeva—could be retired to the attic or dispatched to the thrift store. We had won; our way of life was the wonder of the world. Books from abroad, books from the past, could now be ignored with the sunny insouciance of Ronald Reagan.

But this seemed wrong. The missing books were good books; they were fascinating books. There had to be an audience for them. There was, for example, the audience—sophisticated and inquiring enough—commanded by the New York Review of Books, our relative with offices down the hall. The question was how to reach those readers.

Through a list, I thought—a series. That seemed obvious. The idea and character of the list were just as important to the endeavor as the books on it; or, rather, if the endeavor was to find readers for those books, the best way to do it was through a list.

List is etymologically related to love (and lust), and back when I cut my teeth on books there were all sorts of lists—Anchor, Mentor, Meridian, Obelisk, New Directions Books—that helped, as the names of the imprints were not shy to suggest, to orient the aspiring reader. Additionally, quite often, in the back of each book on such lists there was a list of other books on the list (a literal backlist). These series had recognizable cover designs. They looked sharp. A list like one of those was what we needed, even if, in 1999, they too had, puzzlingly, largely disappeared.

A series of lost books then, but of course countless books have been lost, for all sorts of reasons, good and bad. Which ones should go on our list?

Well, the best ones, of course—but no, that wasn’t the answer. The best books in the sense of canonical books remain, for the most part, readily available. What tend not to be available are those books that don’t fit into a given history of literature or thought or feeling—the books that introduce us to things other than what we know best, that put the question of what a good book is in play or that raise the different but related question of what makes a book timely, however old it may be. What we needed was a series that had the originality, individuality, and authority that any good book must have, but that displayed a life of its own comparable to any real reader’s reading life, moving in and among different books and kinds of books with an explorer’s spirit.

It was with that goal in mind that, 20 years ago, the NYRB Classics series was born. There are more than 500 books in the series now, and what began as a work of memory of reviving books and a way of publishing books that had fallen out of currency remains a work in progress. We have done our best to mix things up—such as by putting Eve Babitz’s Eve’s Hollywood alongside Alexander Berkman’s Prison Memoirs of an Anarchist—and we have published, I think, some truly great books: in the last year, for example, Uwe Johnson’s Anniversaries and Vasily Grossman’s Stalingrad were both translated into English for the first time. I am sure that, happily and in spite of everything, there are other extraordinary and utterly unexpected books waiting for us out there. We are looking for them.

Edwin Frank is the editorial director of NYRB Classics.