Not many mono pressings were made in the USA, since the labels were (mostly slowly but steadily) reducing mono to where, by 1969, everything would be 'single inventory' stereo (or whatever). But in England, where mono would be more commonplace for a few more years, a mono pressing was made, and remains easier to find than the US edition.
It helped that "Nights" became a hit before the album got full release. And though it was only a minor seller back in 1968, the single did help make DOFP a sleeper success in the US, and over the next few years, as the band toured, it sold quite well.
Actually it was 1968 for the US album, and yes, it's a fold down, as are the next three UK mono editions. Singles were sometimes dedicated mixes, though.
From 1968 onward, mono LPs may have been pressed, but they were promo only. Case in point: Frank Zappa's We're Only in It for the Money and The Velvet Underground's White Light/White Heat, both released in 1968 had unique mono mixes and mono LPs were pressed, but they were promo only. There were never stock US mono copies that you could buy in stores. Another example was The Beatles' White Album, released in 1968. There is a mono mix, but it was never released in the US, only in the UK.
Actually some stock copies of both titles exist, but are few and far between. As for promos, once stock mono pressings were eliminated, promo mono's (on almost any label) were usually folds, not dedicated mixes. But it wasn't until 1969 that stock mono was all but gone in the US; there were quite a lot in 1968, just in reduced numbers. As for the WHITE ALBUM, the UK mono press was a strong selling import title for years since it was indeed unavailable here.
ED
