Voters in Portland, Me., made their city the first on the East Coast to legalize marijuana on Tuesday.
Shortly after the polls closed, the Portland Press Herald said the measure would pass easily, and supporters had already claimed victory.
The Portland law will allow residents to possess up to 2.5 ounces of marijuana. Proponents spent $2,500 to buy pro-pot billboards on city buses and in bus shelters to get it passed.
As polls show a majority of Americans now backing legalized pot, marijuana issues were on the ballot in two other states.
In Colorado, voters were expected to decide whether to approve a 25 percent pot tax.
And in Michigan, voters in three cities were to decide whether to remove all penalties for possession.
The votes are the first since last November, when both Colorado and Washington state approved the recreational use of marijuana for all adults 21 and older. Those plans are set to take effect next year.