WASHINGTON — The Supreme Court on Monday decided to let stand rulings that allow same-sex marriage in Virginia, Utah, Oklahoma, Indiana and Wisconsin, a surprising move that may clear the way for the expansion of such unions throughout the nation.

The court’s decision came without explanation and puts off a ruling about the constitutionality of gay marriage that would apply to all 50 states. But it sent a clear signal that a majority of the court did not feel the need to overturn lower court decisions that found state prohibitions were unconstitutional.

Marriages that had been on hold in the five states that were before the court began taking place a few hours later.

At 1 p.m., the U.S. Court of Appeals for the 4th Circuit issued an order that allowed same-sex marriages to begin in Virginia. The first same-sex marriages were performed in Charlottesville and Richmond shortly after 1 p.m. At the same time, the commonwealth recognized marriages performed in states already as legal.

“This is a historic and long overdue moment for our Commonwealth and our country,” Virginia Gov. Terry McAuliffe said in a statement.

Clerks in Marion County, Ind., and Dane County, Wis., began issuing licenses to same-sex couples before noon. In Oklahoma, the Tulsa County Court Clerk’s Office issued a marriage license to Mary Bishop and Sharon Baldwin, the couple who successfully challenged the state’s ban on gay marriage, the Associated Press reported. Utah was expected to follow suit as soon as the 10th Circuit Court of Appeals ordered the state to issue licenses.

The Supreme Court’s decision will likely expand same-sex marriages to other states covered by the federal appeals courts that already have ruled that the bans are unconstitutional, including Colorado, Wyoming, Kansas, West Virginia, North Carolina and South Carolina. The Colorado attorney general said Monday that once the 10th Circuit Court issues its final ruling, clerks in his state have been ordered to begin issuing licenses. That would bring to 30 the number of states where gays can marry.

“I’m blown away by this,” said James Esseks, a lawyer who heads the American Civil Liberties Union’s legal efforts concerning gay marriage. “It is a watershed moment for the entire country.”

Opponents of same-sex marriage said the fight is not over.

“The court’s decision not to take up this issue now means that the marriage battle will continue,” said Byron Babione, senior counsel at the Scottsdale, Ariz.-based Alliance Defending Freedom, which has been active in defending prohibitions against same-sex marriage. “The people should decide this issue, not the courts.”

Victoria Cobb, president of the Family Foundation of Virginia, used the same argument, saying she believes the status of same-sex marriage in Virginia should never have been up to the judicial branch to begin with.

“It’s disappointing that we’re even in the hands of the court, especially since the attorney general chose to not even defend the constitution, the will of the people, left the people defenseless, and now we’re waiting on a court,” Cobb said at a news conference in Richmond.

It was a move that stunned those who closely watch the court. Even though no appeals court had ruled that state prohibitions were constitutional – and such disagreements between federal circuit courts usually are precursors to Supreme Court review – most thought the court would not let such a significant change happen without its input.

But Esseks said that Monday’s action indicates that it does not matter whether an appeals court now rules that state prohibitions are constitutional.

“If that happened, the court will clearly take the case and decide the issue,” Esseks said. “But Monday’s decision is more than a hint about what the court will do.”

There are challenges to same-sex marriage prohibitions in every state. Two appeals courts, in Cincinnati and San Francisco, have heard challenges and could rule at any time.

And the Supreme Court could still take up the issue of same-sex marriage later in this term after more states weigh in.

Same-sex marriage has been legal in Maine since the end of 2012.

In June 2013 the court struck down part of the Defense of Marriage Act, which had denied federal recognition of same-sex marriages performed in states where it was legal. Although that decision did not touch on whether state bans were unconstitutional, a number of federal court decisions have ruled since then that the reasoning of the opinion written by Justice Anthony Kennedy commands such a finding.

The split in federal and state courts since last year’s ruling in U.S. v. Windsor has been 40 to 2 that state prohibitions violate the Constitution’s guarantees of due process and equal protection.

The Windsor decision was decided on a 5 to 4 vote, with the court’s liberals – Justices Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan – joining Kennedy.

It takes only four votes, however, to grant review of lower court decisions. So that means at least one of those who voted no in Windsor – Chief Justice John Roberts and Justices Antonin Scalia, Clarence Thomas and Samuel Alito – were unwilling to force the court to take up the issue now.

The court’s decision not to hear the cases could be a part of Ginsburg’s strategy. Last month, the justice questioned whether there was a need for the court to act now since there was no disagreement among the appeals courts. She has long been an advocate for courts to move incrementally on such controversial social issues. For instance, she believes the court’s broad ruling in Roe v. Wade hardened opposition.

With same-sex marriage apparently imminent in 30 states and the public increasingly in favor of it, the situation now appears more closely like that when the court ruled that prohibitions on interracial marriage were unconstitutional. The Supreme Court waited until most states – 34 – had decided the issue of interracial marriage for themselves before it ruled.