Hmm, what a surprise! I did a little digging and found an article that says Nixon started it. Here’s an exerpt:
Office of National Drug Control Policy (ONDCP). President Nixon started this war in 1969, and President Reagan kicked it into high gear. It’s been a full-throttle battle since, even through the Clinton years.
http://www.inthesetimes.com/article/3501/women_behind_bars/