The state had been the only holdout in the Northeast with a law passed in 1996 still on the books. Pennsylvania is more socially conservative than its neighbors and did not recognize civil unions.
U.S. District Judge John E. Jones III, sitting in Harrisburg, the state capital, ruled that the
ban is unconstitutional. His decision came a day after an Oregon judge overturned that state's law and a few days after the 10th anniversary of same-sex marriages becoming legal in Massachusetts.
The lawsuit sought legal gay marriage in Pennsylvania and recognition of marriages contracted legally elsewhere.
Kathleen Kane, Pennsylvania's Democratic attorney general, refused to defend the state law. The Office of General Counsel, which reports to Gov. Tom Corbett, a Republican, hired former state Supreme Court Justice William Lamb to represent the state.
The American Civil Liberties Union, representing 11 gay couples, the children of one couple and a woman whose partner has died, argued the U.S. Supreme Court ruling striking down the federal Defense of Marriage Act means that banning gays from marrying violates the Equal Protection Clause. Lamb argued that the decision gives states a stronger right to make laws on marriage.