Comparing the US now with the US before 1914 is idiotic. We have a completely different culture now than we did back then. Our moral standards are lower today. We did not have a mass media back then that glamorized getting high. We did not have a whole generation of kids being raised in single-parent homes. Methods of drug distribution were far less sophisticated back then, etc, etc, etc.
The best comparison is the US before and after 1914, and the fact is that cocain and opium use declined dramatically after 1914. DRUG PROHIBITION WORKED, unlike alcohol prohibition. That's why it was never repealed, unlike alcohol prohibition. Drug use continued at minimal levels until our culture went to hell the late 1960's and 1970's.
Your above statment is a perfect way to produce steam from a pro-drug Libertarians ears and have them automatically knee jerkingly say, "that does not compute".
That and mention the devastation opium did to 19th century China.