A divided Delaware state Senate voted Tuesday to make their state the 11th in the nation to allow same-sex marriage, after hearing hours of passionate testimony from supporters and opponents.

The Senate's 12-9 vote sends the bill to Democratic Gov. Jack Markell, who supports the measure and planned to sign it later in the day. It would go into effect July 1.

"I think this is the right thing for Delaware," the governor said after the vote, while posing for pictures with supporters outside his legislative office. "It took an incredible team effort."

Gay rights activists and their supporters in the chamber erupted in cheers and applause following the Senate vote.

Delaware's same-sex marriage bill was introduced in the Democrat-controlled legislature last month, barely a year after the state began recognizing same-sex civil unions. The bill won passage two weeks ago in the state House on a 23-18 vote.

While it doesn't give same-sex couples any more rights or benefits under Delaware law than those they have in civil unions, supporters argued same-sex couples deserve the dignity and respect of married couples. They also noted that if the U.S. Supreme Court strikes down the Defense of Marriage Act, which bars married gay couples from receiving federal benefits, civil unions would not provide protections or tax benefits under federal law to same-sex couples in Delaware.

Opponents, including scores of conservative religious leaders from across the state, argued same-sex marriage redefines and destroys a centuries-old institution that is a building block of society.

Under the bill, no new civil unions will be performed in Delaware after July 1, and existing civil unions will be converted to marriages over the next year. The legislation also states that same-sex unions established in other states will be treated the same as marriages under Delaware law.

The bill does not force clerics to perform same-sex marriages that conflict with their religious beliefs. But under an existing Delaware law banning discrimination based on sexual orientation, business owners who refuse to provide marriage-related services to same-sex couples for reasons of conscience could be subject to discrimination claims.

Delaware joins neighboring Maryland and the nearby District of Columbia as jurisdictions that have approved gay marriage. Last week, Rhode Island became the 10th state to allow gay and lesbian couples to wed, with independent Gov. Lincoln Chafee signing the bill an hour after its final passage.

During arguments in favor of the bill, Delaware Senator Karen Peterson, a co-sponsor of the legislation, announced for the first time publicly that she is gay, and has a same-sex partner of 24 years. The two entered into a civil union privately last year.

“If my happiness somehow demeans or diminishes your marriage, you need to work on your marriage,” Senator Peterson said. ”We don’t need to be fixed. We’re not broken.”

“No one chose to be gay. We are what God made us. We’re not seeking to redefine marriage, but to expand it, just as Loving v. Virginia did,” Peterson said.