There were several lines which operated a/c with "sleeper" accommodations, originally in transcontinental service, later transoceanic flights.

The DC-3, the mainstay of air travel for years, was configured with beds, not unlike a RR Pullman car, by a couple of lines, but with capacity much reduced from the original 21 pax (1/2 config) and later 28 pax models (2/2) in standard service. Physically "bigger" (and heavier) than the RJs, the day's technology limited the weight and number of pax it could carry.

The most spacious of the piston engine passenger a/c "across the oceans" was the Boeing Stratocruiser, developed from the US B-29 and a civilian version the C-97/KC-97. One of the airlines actually had a cocktail lounge on the small lower deck ahead of the freight/baggage holds.

Only the advent of the "Super Connie" and the DC-7C guarnteed "real" nonstop Transatlantic service, especially Westbound "into the wind". One of my first transatlantic flights involved a military flight, McGuire (NJ)/Goose Bay/Thule/Keyflavik/Prestwick/Rhein Main, a long time aloft in the back of a C-130 hauling priority cargo - no insulation, cold, noisy and "paratroop" canvas benches.

Of course, passenger loads were much smaller even in jets, with the original 707 in non-stop Transatlantic service carrying 80 or so, IIRC.