Orlin Wagner, Associated Press
Andrew Schuerman, left, talks during a news conference at the ACLU of Missouri office in Kansas City, Mo., Wednesday, Feb. 12, 2014. Partner James MacDonald holds their daughter Grace during the announcement. The ACLU has filed suit challenging Missouri law denying legal recognition of the marriage of eight couples.

ST. LOUIS — The American Civil Liberties Union filed a lawsuit Wednesday seeking to force Missouri to recognize same-sex marriages performed in places that allow them, saying the state's refusal to do so "undermines the couples' ability to achieve their life goals and dreams."

The ACLU filed the lawsuit in a Kansas City state court on behalf of eight same-sex couples who live in Missouri and were married elsewhere. About an hour later, a federal judge in Kentucky issued a ruling striking down part of that state's constitutional ban on gay marriage and forcing Kentucky to recognize out-of-state same-sex marriages.

Among those who want Missouri to recognize their marriage are Janice Barrier and Sherie Schild, of St. Louis County, who have been together for 33 years and who got hitched in Iowa in 2009. Both Barrier, 61, and Schild, 60, have battled cancer in recent years, and they worry about what the future holds if the state refuses to recognize their marriage.

"We're really concerned that if one of us would end up in a nursing home we might not have the same rights to care for each other in privacy that different-sex married couples enjoy in Missouri," Barrier said. "It's so very important to us that we're not torn apart at the very end of our lives."

At a St. Louis news conference to discuss the ACLU of Missouri's lawsuit — similar events were held in Kansas City, Jefferson City and Springfield — attorney Tony Rothert said the ACLU has a "50-state strategy" to push for the legalization of same-sex marriage throughout the country. He declined to say if or when legal action will be taken seeking to force Missouri to legalize same-sex marriage.

After a Massachusetts Supreme Court ruling permitted gay marriage in that state, Missouri in 2004 became the first state to enact a constitutional amendment prohibiting same-sex marriage. The measure was approved by 70 percent of Missouri voters.

Gay marriage opponents contend that marriage should be restricted to being between a man and woman, and say they hope judges will allow states to choose their own path. Missouri's Republican-led Legislature has shown no interest in changing the state's policy of not recognizing same-sex marriages performed in one of the 17 states or in countries that allow them.

"The people of Missouri have made clear that they cherish the institution of marriage, and strongly oppose efforts to weaken, redefine, or transform its nature and purpose," Joe Ortwerth, executive director of the Missouri Family Policy Council, said in a statement. "We are optimistic that the Missouri Supreme Court will affirm U.S. Supreme Court precedent that states are constitutionally entitled to preserve the traditional family unit as the cornerstone of our civilization."

The ACLU says the policy is unfair.

"The refusal to recognize plaintiffs' marriages undermines the couples' ability to achieve their life goals and dreams, threatens their mutual economic stability, and denies them a dignity and status of immense import," the lawsuit argues.

Throughout the country, courts and the federal government have increasingly been moving toward allowing and recognizing same-sex marriage. On Tuesday, Nevada's attorney general and governor said the state will stop defending its constitutional ban on same-sex marriages, a case that was pending before a federal appeals court. And a gay rights group in Louisiana scheduled a Wednesday news conference to announce it would challenge that state's constitutional ban against recognizing gay marriages performed elsewhere.

Missouri Gov. Jay Nixon drew criticism from gay marriage opponents in November when he directed the state Department of Revenue to accept joint tax returns from same-sex couple who are legally married in other states. The state attorney general's office has said the policy appears to comply with Missouri law.

The directive prompted a lawsuit filed by same-sex marriage opponents, and led a Republican lawmaker last week to file articles of impeachment against the Democratic governor.