Opponents spent months networking through black and Catholic churches, trying to convert strength in the pews to muscle at the ballot box. Their less-frequent ads warned of changes to school curriculum and other consequences if voters redefined marriage.

At an event last week featuring about 75 religious leaders opposed to Question 6, Derek McCoy, the leader of the opposition group, argued that “marriage is more than what any two adults want. It is about future generations and our culture.”

The battle in Maryland drew an array of celebrities from across the country, with most offering fundraising help for supporters of same-sex marriage.

Before Tuesday, same-sex marriage was legal in the District and six states: Massachusetts, Vermont, Connecticut, New Hampshire, Iowa and New York.

Tuesday’s ballot measure in Washington state bears the most similarities to Maryland’s. In those states, legislatures passed a measure that petitioners pushed to a popular vote. A mail-in voting procedure in the Evergreen State means that final results there won’t be known till week’s end.