WASHINGTON — The Supreme Court is getting back in the marriage business.

The justices agreed Friday to decide a major civil rights question: whether same-sex couples have a right to marry everywhere in America under the Constitution.

The court will take up gay-rights cases that ask it to overturn bans in four states and declare for the entire nation that people can marry the partners of their choice, regardless of gender. The cases will be argued in April, and a decision is expected by late June.

The court chose not to decide this issue in 2013, even as it struck down part of a federal anti-gay marriage law that paved the way for a wave of lower court rulings across the country in favor of same-sex marriage rights.

At that time, just 12 states and the District of Columbia permitted gay and lesbian couples to wed. That number has jumped to 36, almost all because of lower court rulings.