A Delaware Senator and her partner, became the first same-sex couple to marry, as the state’s new equal marriage law came into effect.

State Senator Karen Peterson, and her partner Vikki Bandy, both 63-years-old, married on Monday morning.

They had previously entered into a civil union, but Monday’s ceremony converted it to marriage, in a brief ceremony attended by friends and family, reports the AP.

Following the ceremony, other couples lined up to marry. Monday was the first day that Delaware’s new equal marriage law came into effect.

Back in may, lawmakers in the US state of Delaware voted 12 to 9 in favour of a bill to legalise equal marriage, making the Diamond State the 11th to allow same-sex marriage.

The Senator came out as a lesbian during her speech to convince colleagues to vote in favour of same-sex marriage, which was the first time that Ms Peterson has disclosed publicly that she is in a 24-year-old relationship with Ms Bandy.

At the time, she said:“My partner Vicki and I have been together for 24 years,” she said. “Last year, we entered into a civil union.”

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