First revolver was 1966, a Colt Cobra .38 Special. Used the M1911A-1 quite a bit while in the Army 1968-72. Picked up a Belgian Browning Hi Power while in Vietnam. Got out of the Army and became a cop, with revolvers being required for duty use.
Other than the Colt Government Model (and Commander variant), Browning Hi Power, surplus Lugers & P38's, about the only semi-autos commonly seen in those days were various European pieces. S&W introduced the Model 39 during the 1950's, and it had become moderately popular through the 1960's (Illinois State Police and a few others adopted it). Then about 1972 S&W brought out the Model 59, about the first domestically produced "large capacity" pistol (15 rounds), and we started seeing more semi-autos on a regular basis. When the military announced the M9 Beretta (1985) we started seeing more and more automatics. Shortly thereafter Glock hit the market and the change accelerated, with most other makers offering multiple pistols by the end of the 1980's. By the early 1990's it was becoming less common to see cops with revolvers in their holsters, and the market was overflowing with used revolvers for a few years (wish I'd had the foresight to pick up all the good S&W's that were available for peanuts during that time).
I think the general public's buying preferences were influenced by two forces; the first being a general police transition to semi-autos, the second being movies and TV shows featuring all the newest hardware.