BREAKING: Marriage Lawsuit Filed in North Dakota

The last state in the union with an unchallenged anti-marriage equality law just lost that status, as seven same-sex couples filed a lawsuit in federal district court today seeking to overturn North Dakota's constitutional amendment banning same-sex marriage.

The lawsuit was filed by Minneapolis-based attorney Josh Newville, who also filed last month's lawsuit challenging South Dakota's constitutional ban on same-sex marriage.

With today's filing in U.S. District Court in Fargo, N.D., all 31 states with statutory or constitutional measures denying marriage rights to same-sex couples are now facing legal challenges, notes the Associated Press.

Today's lawsuit brings the total pending cases seeking marriage equality in states across the country to 71, according to advocacy group Freedom to Marry. Since the U.S. Supreme Court issued its landmark June 2013 ruling in U.S. v. Windsor, striking down a key section of the federal Defense of Marriage Act, every state and federal court that has considered bans on same-sex marriage has found those policies to be unconstitutional. Three of the federal challenges -- regarding Utah, Oklahoma, and Virginia -- have already been heard in federal appeals court, while appeals are pending in a total of six federal circuits, according to Freedom to Marry. Same-sex couples can currently wed legally in 19 states and the District of Columbia.