Washington state is on track to become the ninth state to approve gay marriage as opponents of a referendum there conceded Thursday afternoon:

"With added results showing that we have not closed the gap, it now appears clear that Referendum 74 will be narrowly approved," said Joseph Backholm, chairman of Preserve Marriage Washington, which worked to defeat the measure.

Voters in Maryland and Maine also approved same-sex marriage measures on Tuesday, while Minnesota voters rejected a constitutional ban on it.

Before this week, no states had ratified same-sex marriage via popular vote. 

 The Fix has a list of other "firsts" from this week's election.