I noted with interest last Saturday the card catalogue* in the Hendel Library of the Lyman Allyn Museum in New London, Connecticut, which I was visiting for the first time (though I have lived in Connecticut since 2006). I noticed the familiar build-in wood drawers for the cards, and on a whim opened one of them, expecting to find it empty (as usual). To my surprise, I encountered real catalogue cards and nary a library computer in sight.
I hasten to add that the Hendel Library is a beautifully furnished room in the Deshon-Allyn House, built in 1829, and which combines Federalist and Greek Revival design elements. The library is not really a functioning library, but an event space available for rentals. I expect that the collection has been static for decades, and some of the books probably exhibit familiar problems of aging and minimally cared-for collections. The room features a large hand-crafted model ship by Pasquale Montesi, an Italian immigrant and former sailor in the Italian navy, who settled in nearby Norwich in 1898, and ran a fish market there. Montesi crafted his models on the basis of memory and intimate knowledge of sailing ships, without blueprints or drawings. (Hence the design elements are not to scale.) Most visitors to the Museum see an elegant room with a large ship model, and ignore the surrounding library.
I began to wonder: how many card catalogues still exist? Where are they located? Are any actively maintained? —even informally, and not according to cataloguing rules as known to several generations of cataloguers, since OCLC printed its last catalog card on October 1, 2015 (sent to the now-defunct Concordia College of Bronxville, N.Y.), and Library of Congress Distribution Service (still active digitally) printed its last card in 1997. I am considering putting out a call to discover where card catalogues still exist. This is not to fetishize card catalogues: I wouldn't want to go back to them, but they are or were a notable technology in building scholarship and literature in the 20th century.
In the meantime, the Library of Congress published a interesting & fun book in 2017: The Card Catalog: Books, Cards, and Literary Treasures, by Paul Devereaux (with a forward by the Librarian of Congress, Carla Hayden). Worth a look.
*A note on spelling: catalog and catalogue are both acceptable in American usage. Catalog is sometimes used as a noun, and catalogue as a verb. Catalogue as a usage predominates in British and world-wide usages. I prefer catalogue (and I was once a cataloguer, but for me the spelling is not a matter of doctrine or politics.