Minnesota became the 23rd state to legalize marijuana when Gov. Tim Wald signed the legalization measure into law. (It's also legal in Washington, D.C., with oddball restrictions, and my home state, Oklahoma, has medical marijuana that is so wide open it amounts to de facto legalization).
Jacob Sullum at Reason magazine has the relevant details: "Adults 21 or older will be allowed to possess two ounces or less of marijuana in public, share that amount with other adults, keep two pounds or less at home, and grow up to eight plants, four of which are mature. Those provisions take effect on August 1."
The Democrats who control Minnesota have passed a big stack of bills, aside from legalizing cannabis; if you are curious, here is a list.
Ohio, where I live, may have legal marijuana on the ballot; it's not clear yet. Ohio has relatively strict medical marijuana; there is a list of qualifying conditions and you have to submit medical records proving you have at least one of them.