MADISON, Wis. -

Wisconsin has appealed a federal judge's ruling from last month striking down the state's ban on same-sex marriages as unconstitutional.

Republican Attorney General J.B. Van Hollen filed the appeal on Thursday as he indicated at the time of the original ruling he would. U.S. District Judge Barbara Crabb ruled on June 6 that the ban, approved by voters in 2006, was a violation of gay couples' equal protection and due process rights.

For one week more than 500 same-sex couples got married in the state before Crabb put her ruling on hold pending the expected appeal.

The appeal will be heard by the 7th U.S. Circuit Court of Appeals in Chicago.

The lawsuit was brought by the American Civil Liberties Union on behalf of eight same-sex couples.