Thirty-two states that either allow gay marriage or have banned it asked the U.S. Supreme Court on Thursday to settle the issue once and for all.

Fifteen states that allow gay marriage, led by Massachusetts, filed a brief asking the justices to take up three cases from Virginia, Utah and Oklahoma and overturn bans. And 17 other states, led by Colorado, that have banned the practice asked the court to hear cases from Utah and Oklahoma to clear up a "morass" of lawsuits, but didn't urge the court to rule one way or another.

The filing came as a three-judge panel of the 7th U.S. Circuit Court of Appeals in Chicago ruled that same-sex marriage bans in Wisconsin and Indiana are unconstitutional. The unanimous decision Thursday criticized the justifications both states gave, several times singling out the argument that marriage between a man and a woman is tradition. There are, the court noted, good and bad traditions.

The experience of Massachusetts — the first state to legalize gay marriage — shows that allowing same-sex couples to wed has only benefited families and strengthened the institution of marriage, said Attorney General Martha Coakley.