When I started programming professionally in the 1980's there were really only two choices, RCS and SCCS, neither of which were networked, and which were really only readily available on Unix. I suppose there were commercial products for DOS (this was pre-Windows), but again, not readily available. If you wanted better, you had to roll your own.

Later, for SunOS, we had big, expensive systems like ClearCASE and Harvest that were (as I recall) weird as all get out, over-engineered, expensive (did I mention expensive?) and all too often designed for the convenience of the management, not the programmers.

Then there was CVS, which was a revelation. You didn't have to have a server, if you wanted to use it locally, all by yourself; I did that on my personal laptop. Otherwise you needed to set up a server. Subversion was an improvement. And then came Git (and Fossil, et al) and the world changed forever.