How did Charles Manson find all those misguided people?

I just read that Charles Manson died. All that stuff was before my time but there is no shortage of information about him and his “Family”.
One thing I do not understand.

How did he find so many people who were willing to commit savage murder and collect them into one place?

Especially young girls. Not that girls can’t be killers, but more often it is the guys who kill.

It isn’t as if he could put out a want ad in the papers, or post it on Facebook.