GLBT rights group Equality Matters has reported that 42 percent of the US population now lives in states where same-sex couples are recognised in law.
Forty-one percent of Americans live in states that allow same-sex couples to commit to each other in state-recognised unions performed in those jurisdictions, through marriages, civil unions, or domestic partnerships.
Another 1 percent live in New Mexico, which recognises same-sex relationships formalised in other states while not formalising them itself.
Thirty percent of Americans live in states which grant same-sex couples identical rights to married heterosexual couples, while 7 percent live in states that allow same-sex couples to marry.
The percentage does not include people who live in cities and counties that have passed ordinances recognising same-sex couples where their state legislatures do not.
However, under the Defense of Marriage Act, same-sex couples do not have access to the rights or benefits granted to married couples under US federal law.