Within the field of history, the graph at the beginning of this post from the AHA shows that the 1970s was an absolutely terrible decade: https://www.historians.org/publications-and-directories/pers...

What happened was a big drop in the number of new PhDs. That is why the 1980s and early 1990s might have had okay job markets. By about 1991/1992 the job market was once again saturated.

Yes, in the 1960s. Universities were expanding rapidly to respond to the influx of baby boomers, and humanities majors were much more popular, so it was relatively easy to get hired.[0]

It's pretty much been varying degrees of bad since then, but as the first chart in [1] shows, it got a lot worse after 2008.

[0]: https://www.historians.org/publications-and-directories/pers...

[1]: https://www.historians.org/publications-and-directories/pers...