Delaware on Tuesday became the 11th state to permit same-sex marriage, the latest in a string of victories for those working to extend marital rights to gay and lesbian couples.

The marriage bill passed the State Senate by a vote of 12 to 9 Tuesday afternoon.

“It’s a great day in Delaware,” said Gov. Jack Markell, a Democrat, who signed it within minutes of passage before an overjoyed crowd of activists. “I am signing this bill now because I do not intend to make any of you wait one moment longer.”

Same-sex couples will be eligible for marriage licenses on July 1.

Delaware adopted same-sex marriage just five days after a similar decision in Rhode Island and after ballot-box victories last fall in Maine, Maryland and Washington.

During three hours of emotional debate before the vote Tuesday, State Senator Karen Peterson, a Democrat, said she had lived with a female partner for 24 years, and she challenged opponents of extending marriage to gay couples. “If my happiness somehow demeans or diminishes your marriage, then you need to work on your marriage,” she said, eliciting cheers and laughter.