Here is an interesting synopsis of the legal history of marijuana in Canada (and the racist origin):
http://www.thestar.com/news/canada/2...o_with_it.html
It became illegal in Canada when someone hand-wrote it onto the list of banned substances just prior to it being passed (the previous editions did not have it on there). There was no debate in parliament and no one knows who added it. It very well may not have even have been anyone elected or with special knowledge on the subject.
http://www.cbc.ca/news/health/mariju...-why-1.2630436