The Minnesotan Senate approved marriage equality after several hours of debate on Monday with a vote of 37-30. The state’s House passed the bill last week in a vote of 75-59.
Minnesota’s governor has indicated he is likely to sign the bill into law Tuesday.
Anti-gay Minnesotan congresswoman Michele Bachmann tweeted shortly before the Senate debate that she was proud of her record trying to prevent same-sex couples from marrying.
“I’m proud to have introduced the original traditional marriage amendment, and I thank all Minnesotans who have worked so hard on this issue,” she wrote.
Last week, Delaware became the 11th state to legalise same-sex marriage. The state’s Senate passed a same-sex marriage bill with 12 votes to nine.
It was signed into law by Delaware’s Democrat Governor Jack Markell shortly after the vote.
It too came just days after Rhode Island’s governor signed similar legislation into law, after its Senate passed a marriage equality bill last month.
The state’s Lower House had already approved the bill two weeks ago with 23 votes to 18.
Under the new laws, Delawareans can get married from July 1 and a mechanism will convert existing civil unions into marriages.
The bill does not force clerics to perform marriages for same-sex couples.
A gay marriage bill is also under consideration in Illinois.