The <a href="https://en.wikipedia.org/wiki/Marihuana_Tax_Act_of_1937" id="mwzA" rel="mw:WikiLink" title="Marihuana Tax Act of 1937">Marihuana Tax Act of 1937</a> is passed in America, the effect of which is to render <a href="https://en.wikipedia.org/wiki/Cannabis_(drug)" id="mwzQ" rel="mw:WikiLink" title="Cannabis (drug)">marijuana</a> and all its by-products illegal.