“Sexual intercourse began / In nineteen sixty-three,” Philip Larkin famously wrote in Annus Mirabilis. According to his Wikipedia biography it actually began for him in 1945, but he seems to have liked the rhyming possibilities of three (me, LP) more than those of five.
For me, the year was 1959, and what began was making love. It may not have been the year of my first sexual experience, but it was the first time in my life that it was called making love. It also happened to be the year of “the end of the Chatterley ban” that Larkin alludes to in his poem.
Coincidentally, it was in Alfred Hitchcock’s North by Northwest, released in 1959 that I last heard to make love used (by Cary Grant’s character to Eva Marie Saint’s) in its old-fashioned sense of ‘to pay amorous attention; to court, woo’ (as given by the Oxford English dictionary, which adds “Now somewhat arch.“).
The OED also gives a few pre-1959 citations of the sense ‘to engage in sexual intercourse,’ including one from Hemingway, but they are ambiguous. In fact, making love could well mean whatever it is that people do to each other when they are in love, possibly but not necessarily including sexual intercourse. When Cole Porter wrote (in Night and Day), “And its torment won’t be through /Till you let me spend my life making love to you,” it’s unlikely that he envisioned the song’s first-person subject to want to spend the rest of his life courting or wooing (or even paying amorous attention to) it’s second-person object.
Then there is the movie Let’s Make Love, which was not released until 1960. The verb phrase of the title was used only, as far as I remember, in the song-and-dance number performed by Marilyn Monroe and Frankie Vaughan. For its time it was quite suggestive — Marilyn, resplendent in a plunging gown, undoes Frankie’s bow tie! She takes off her high-heeled shoes! — but evidently tame enough to receive the MPAA seal of approval. Given the year of release, the song (by Cahn and Van Heusen) was, in all likelihood, written… in 1959.