Michigan became the 13th state to approve the use, possession and growth of marijuana by patients suffering from HIV/AIDS, cancer and other conditions, the Detroit Free Press reports.

The Marijuana Policy Project, a Washington, DC–based advocacy group that supports marijuana law reform across the country, spent $1.7 million on making Michigan voters aware of Proposal 1 by collecting petition signatures and countering a campaign against medical marijuana.

Though law enforcement and medical organizations opposed the initiative—claiming that it would lead to increased crime and juvenile drug use—the state's voters passed the initiative with 63 percent in favor of medical marijuana.