At the Marijuana Investor Summit on April 22, 2015, attorneys Marc Ross, partner at Sichensia Ross Friedman Ference, and Michael McGrory, partner at SmithAmundsen, explored the history of marijuana laws and the factors that will shape the future of marijuana legislation.

The future they portrayed involves unsteady compromise. It will include balancing the interests of states, patients and doctors and will be shaped by state decisions about which medical conditions may be treated and how the market process from cultivator to consumer is regulated. There are more questions than answers, but understanding history and knowing the key issues can be powerful for stakeholders as they consider how to participate in the emerging world of legal marijuana.

Modern marijuana history begins in the United States in the 1920s as it headed north over the Mexican border. By the 1930s the federal government had stepped in, establishing the Federal Bureau of Narcotics, headed by Harry Ainslinger. “Ainslinger’s single mission,” according to Marc...