Cannabis is a Schedule I drug under the Controlled Substances Act (CSA), which means that – despite increasing state legalization of recreational and medicinal use – cannabis businesses remain federally illegal. Nevertheless, the U.S. constitutional framework, certain federal laws and related guidance provide some level of comfort to those businesses and investors. This article, the first in a four-part series, discusses the legislative, judicial and executive cannabis framework, as well as state legalization and industry growth. The second article will analyze cannabis deal structures, how managers should diligence investments, what managers should include in offering documents and anti-money laundering concerns. The third article will evaluate the effect of federal illegality on underlying businesses, as well as residency requirements for investing. The fourth article will assess the international prospects for investing, including in Canada; public perception and valuation issues; and service providers in the space. See “Opportunities and Challenges Posed by Three Asset Classes on the Frontier of Alternative Investing: Blockchain, Cannabis and Litigation Finance” (Dec. 14, 2017).