Other than drunks on skid row downtown, Los Angeles didn’t have many homeless people in the postwar era. That was largely because of the immense Camarillo State Mental Hospital, which had 7,000 residents/inmates/patients or whatever you want to call them in 1957. For example, Charlie Parker recorded “Relaxin’ at Camarillo” after his six restful months there in 1946 following a series of unfortunate events such as setting his hotel room on fire and playing his saxophone naked in the lobby.
But then progressive geniuses like Erving Goffman and Michel Foucault decided that locking people up just for being lunatics and out-of-control addicts was a mistake. So, now the old asylum is the very pleasant campus of Cal State Channel Islands.
And the lunatics and addicts camp on the sidewalks at Venice Beach.