"The bill ... eliminates criminal offenses for the possession of an ounce or less of marijuana. Anyone caught with marijuana under that threshold would be charged with a civil offense punishable by a $25 fine.

"Support for the measure built after a 2013 report by the ACLU found that D.C. leads the nation in marijuana arrests, and that black residents are eight times more likely to be arrested for marijuana possession than their white counterparts.

"The bill now goes to Capitol Hill for a 60-day congressional review. Congress rarely blocks D.C. laws, but in 1998 it did stop the city from implementing a ballot initiative legalizing medical marijuana. If Congress does not formally disapprove the bill, it will take effect by the summer."