By 2000, French and Brazilian bodyscaping were the norm in the porn industry, in contrast to the 80s and 90 in which full pubes were common unless the talent was trying to signal she was kinky.

In the 70s, the Golden Age of Porn, full pubes were expected (or at most, someone might get a bikini trim, like for wearing a bikini). If someone was trimmed or shaved, it was because she was a French arty bohemian. (I don’t know if the Brazillians were doing it yet.)

Before that, porn was mostly pin ups and underground reels. If you wanted to see below the waist you had to find nudist documentary footage. Also European porn in the mid 20th century dipped as young as 14 years, though 16 was more common. Only after globalization and Europorn was marketing in the US did a hard age floor of 18 years become enforced.

ETA: Before the 21st century in western civ, women’s bits were notoriously mysterious, what with young men trying to sneak a peak and only getting to see bush. Also men’s mags were conscious about showing genitals until the late 80s. (There was an open spat between Playboy and Penthouse about the thresholds of pridishness, tastefulness, and indecency.)