Legal marijuana has officially come to the Midwest.

Under a new measure taking effect Thursday in Michigan, people ages 21 and older in the state can legally possess and use cannabis for recreational purposes. Michigan voters approved the initiative in November with 56 percent of the vote.

Michigan’s Proposal 1 allows for the possession and transportation of up to 2.5 ounces of marijuana ― including up to 15 grams of marijuana concentrate ― and the possession of up to 10 ounces in a nonpublic place. Residents can also grow up to 12 plants at home, though those plants cannot be visible from a public place.

The new law strictly prohibits the public consumption of cannabis. Driving while under the influence of marijuana also remains illegal.

Although the measure calls for state policymakers to begin developing rules and regulations to guide the creation of Michigan’s recreational marijuana industry, officials say retail stores aren’t likely to open until 2020. Proposal 1 also legalized the cultivation of industrial hemp, nonintoxicating strains of cannabis that can be used to make textiles, biofuels and foods.

In response to November’s vote, incoming Michigan Gov. Gretchen Whitmer (D) has also said she intends to grant clemency to some of the thousands of people locked up in state prison for marijuana-related convictions.

With the enactment of Proposal 1, Michigan becomes the 10th state in the U.S. ― and the first in the Midwest region ― to legalize marijuana for recreational use. Michigan voters had previously approved medical marijuana in 2008, and it is one of the more than 30 states to have legalized cannabis for that purpose.

Marijuana legalization has spread rapidly across the U.S. since 2012, when Colorado and Washington became the first two states to pass measures okaying recreational cannabis. But up until now, that movement had been limited to states in New England and the West Coast, as well as Washington, D.C.

Despite the shifting legal landscape of marijuana at the state level, the plant is still a Schedule I substance under federal law, alongside drugs like heroin and LSD. But the American public appears to be increasingly skeptical of that longstanding framework. A full two in three Americans now support legalization, and polling has suggested the issue is becoming increasingly bipartisan.

With Michigan now having joined the ranks of legal marijuana states, it’s only a matter of time before others follow suit, said Matthew Schweich, deputy director of the Marijuana Policy Project, which played a leading role in the organizing support for Proposal 1.

“When it comes to marijuana policy in America, Michigan is ahead of the curve,” said Schweich. “It will serve as a strong example for the many other states that are currently considering similar reforms.”