the criminalization of narcotics in the united states has a long and compicated history, which sets perspective for this conintuing modern debate.
without getting longwinded, and respecting that there are miriad perspectives one could take to interpret that history, here is a one summary that has a good degree of popular acceptance:
it may surprise some people to know that the distribution of almost all narcotics was uncontrolled in the united states until only recently. in the 19th and early 20th centuries, opiates like morphine and heroin and even cocaine were widely available in so-called 'patent' medicines that were sold by travelling salesmen and elsewhere. people could even buy syringes and shooting works from the sears catalog.
there was a national drug problem, where frontier mothers became addicts and actually killed their children by giving them 'sleeping tonics' which were basically pure morphine. this was recognized and the federal government stepped in to create regulatory agencies and procedures at the insistence of the medical community, which was already trying to regulate itself through the formation of professional societies. this lobbying effectively created a huge sector with complicated and expensive means of drug development, distribution, and legalization: the modern pharmaceutical industry, the AMA and FDA.
despite any legitimate health concern, a great deal of the crackdown on narcotics has always been racially motivated. for example, opium dens were brought to the american west with the asian migration, and local governments cracked down on opium to contain and control asian settlements. in the american south, marijuna was a black drug, and white men didn't like it because, among other reasons, when a black man was high, he was less fearful and would look a white man in the eye.
people are sometimes suprised to learn that colonial american settlers cultivated hemp for many reasons, and smoked marijuna for it's narcotic effect. the planting journals of mount vernon and monticello show that experimental agriculturalists washington and jefferson were separating cannibis plants by sex, harvesting buds, and noting the effects of increasing potency by selective breeding, grafting and other horticultural controls. tobacco pipe smoking in colonial culture was more similar to marijuana smoking than it is to how we smoke cigarettes and pipes today. they smoked potent leaves for the nicotine rush and shared pipes at taverns, breaking off small portions of the stem as they were used communally. they adopted this practice from native americans and eventually adapted and refined it. the spaniards are responsible for inventing cigars which eventually led to more accessible cigarettes.
the eventual criminalization of marijuna was in no small part due to the multi media campaign efforts of william randolph hearst, who tapped into the fears and racism of the emerging american middle class. he used his newspaper empire to push public opinion and force policy as well as using the emerging medium of film to create movies like "refer madness" - which now are cult classics. it is suggested that his real motivation was to prevent the use of hemp as alternative source of paper production, since hearst's holdings of timber and paper mills were so substantial that he held an effective monopoly on the production of newsprint during the period when newspapers were the dominant mass medium.
governments were also involved in protecting their national trade interests. the british empire owned the opium trade and expanded strategically to maximize it. when its control eroded , it sought to supress it. this practice mirrors the british suppression of the slave trade to spanish colonies in the early 19th century to re-establish the competitive advantage to its own sugar producing economies.
it has always been about money. the history channel did an amazing series called "Illegal Drugs & How They Got That Way" a while back. certain episodes of it can be watched online at this link:
http://www.pot-tv.net/archive/shows/...howse-770.html