Washington (AFP) – The Supreme Court agreed Friday to rule whether same-sex couples across the United States should have the right to marry, setting the stage for a pivotal decision on the civil rights issue.

The highest U.S. court will examine cases in four states — Ohio, Michigan, Tennessee and Kentucky — which have banned gay marriage.

The court said it would hold a hearing in April to study whether the 14th Amendment requires a state to license a same-sex marriage, and whether a state is required to recognize same-sex marriages which took place out-of-state.

In a landmark decision in June 2013, the Supreme Court struck down a law denying federal benefits to homosexual couples by defining marriage as a union between a man and a woman.

In doing so, it cleared the way for married gay and lesbian couples to enjoy the same rights and privileges under federal law as their straight counterparts.

But it stopped short of legalizing same-sex marriage nationwide, leaving that question to the states.

At that time, only 12 states plus Washington recognized same-sex marriages.

Since then, a patchwork legalization of same-sex marriage has rolled out across America, with 36 states now allowing same-sex marriage.

Same-sex unions in the state of Florida — with its huge swath of southern rural conservatism juxtaposed by large areas of urban liberalism — met with years of resistance before finally being allowed earlier this month.

With a few exceptions, the states that have refused to marry same-sex couples have lost in court, including in front of the Supreme Court.

The question has been up in the air since Massachusetts became the first state to legalize same-sex marriage in 2004.

This story has been updated.

Photo: Matt H. Wade via Wikimedia Commons