However, thinks like PCP, Crack and methamphetamines...

PCP was initially made in 1926 and brought to market as an anesthetic medication in the 1950s (not "homegrown").

Obetrol, patented by Obetrol Pharmaceuticals in the 1950s and indicated for treatment of obesity, was one of the first brands of pharmaceutical methamphetamine products.[150] Due to the psychological and stimulant effects of methamphetamine, Obetrol became a popular diet pill in America in the 1950s and 1960s.

Isn't it a little strange that "society" didn't collapse in the 1950s and 1960s?

Cocaine consumption had grown in 1903 to about five times that of 1890, predominately by non-medical users outside the middle-aged, American, professional class.

...but if you come onto my property acting violent and aggressive you will be shot.

I'm pretty sure you're already allowed to shoot people for trespassing.