To add onto the other comments, I’d like to point out that there are two distinct things that are called liberalism. If you’re in the US, liberalism employed on its own usually refers to social liberalism, ie essentially progressivism. In that regard it is understood as the opposite of conservatism.
https://en.wikipedia.org/wiki/Social_liberalism

In France (and elsewhere), when we say “liberalism” we mean economic (or “classic”) liberalism, which essentially means : free to entreprise, free from the burden of social contribution (few taxes), free from regulations (small government), etc. which is closer to the economic policies that conservatives (and their equivalents over the world) typically defend.

The word iberal is built from the latin root “liber”, meaning free. https://en.wiktionary.org/wiki/liberal

So in practice, there’s a mixup of these terms where for americans/britons liberalism=left, whereas for a lot of other people liberalism=right. Hence the confusion.

For the history side of things, I can’t help… but reading the above article should help already.

Cheers,