• The Supreme Court in a 5-4 decision overturned Roe v. Wade, the landmark ruling that established the constitutional right to abortion.
• Roe since 1973 had permitted abortions during the first two trimesters of pregnancy in the United States.
• Almost half the states are expected to outlaw or severely restrict abortion as a result of the Supreme Court's decision on a Mississippi case known as Dobbs v. Jackson Women's Health Organization.
• Justice Samuel Alito wrote the majority opinion, joined by four other conservatives. The three liberal justices opposed the decision. Chief Justice John Roberts voted with the majority to uphold the Mississippi abortion restrictions but did not approve of tossing out Roe altogether.

The Supreme Court in a 5-4 decision on Friday overturned Roe v. Wade, the landmark ruling that established the constitutional right to abortion in the U.S. in 1973.

The court's controversial but expected ruling gives individual states the power to set their own abortion laws without concern of running afoul of Roe, which had permitted abortions during the first two trimesters of pregnancy.

Follow live coverage of reaction to abortion decision here

Almost half the states are expected to outlaw or severely restrict abortion as a result of the Supreme Court's decision, which is related to a highly restrictive new Mississippi abortion law. The laws will affect tens of millions of people around the country, who may have to cross state lines to seek reproductive health care.

Other states plan to maintain more liberal rules governing the termination of pregnancies.

Supporters of abortion rights immediately condemned the ruling, while abortion opponents praised a decision they had long hoped for and worked to ensure. Protesters descended on the Supreme Court on Friday to speak out both for and against a decision that will upend decades of precedent in the U.S.

Read the Supreme Court decision overturning Roe v. Wade here

Justice Samuel Alito, as expected, wrote the majority opinion that tossed out Roe as well as a 1992 Supreme Court decision upholding abortion rights in a case known as Planned Parenthood v. Casey.

Alito was joined in that judgment by four other conservatives on the high court. Chief Justice John Roberts voted with the majority to uphold the Mississippi abortion restrictions but did not approve of overturning Roe altogether.

The majority also included three justices appointed by former President Donald Trump: Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett.

The court's three liberal justices filed a dissenting opinion to the ruling, which quickly drew protestors to the Supreme Court building on Capitol Hill in Washington, D.C.

"We hold that Roe and Casey must be overruled," Alito wrote.

"The Constitution makes no reference to abortion, and no such right is implicitly protected by any constitutional provision, including the one on which the defenders of Roe and Casey now chiefly rely — the Due Process Clause of the Fourteenth Amendment," Alito wrote.

"That provision has been held to guarantee some rights that are not mentioned in the Constitution, but any such right must be 'deeply rooted in this Nation's history and tradition' and 'implicit in the concept of ordered liberty," he added.

"It is time to heed the Constitution and return the issue of abortion to the people's elected representatives," Alito wrote.

In their scathing joint dissent, the court's liberal justices wrote, "The majority has overruled Roe and Casey for one and only one reason: because it has always despised them, and now it has the votes to discard them. The majority thereby substitutes a rule by judges for the rule of law."

"The majority would allow States to ban abortion from conception onward because it does not think forced childbirth at all implicates a woman's rights to equality and freedom," said the dissent by Stephen Breyer, Sonia Sotomayor and Elena Kagan.

"Today's Court, that is, does not think there is anything of constitutional significance attached to a woman's control of her body and the path of her life," it said. "A State can force her to bring a pregnancy to term, even at the steepest personal and familial costs."

In a concurring opinion with the majority ruling, the conservative Justice Clarence Thomas wrote that in light of the rationale for overturning Roe, the Supreme Court should reconsider its rulings in three other past cases which established a right to use birth control, and which said there is a constitutional right for gay people to have sex and marry one another.

Friday's bombshell decision came a day after the Supreme Court in another controversial ruling invalidated a century-old New York law that had made it very difficult for people to obtain a license to carry a gun outside of their homes.

The case that triggered Roe's demise, known as Dobbs v. Jackson Women's Health Organization, is related to a Mississippi law that banned nearly all abortions after 15 weeks of pregnancy.

Dobbs was by far the most significant and controversial dispute of the court's term.

It also posed the most serious threat to abortion rights since Planned Parenthood v. Casey, in which the Supreme Court reaffirmed Roe.

Dobbs deepened partisan divisions in a period of already intense political tribalism.

The early May leak of a draft of the majority opinion, which completely overturned Roe, sent shockwaves across the country and galvanized activists on both sides of the debate. It also cast a pall over the nation's highest court, which immediately opened an investigation to find the source of the leak.

The publication of the court's draft opinion, written by Alito, sparked protests from abortion-rights supporters, who were outraged and fearful about how the decision will impact both patients and providers as 22 states gear up to restrict abortions or ban them outright.

The leaked opinion marked a major victory for conservatives and anti-abortion advocates who had worked for decades to undermine Roe and Casey, which the majority of Americans support keeping in place.

But Republican lawmakers in Washington, who are hoping to win big in the November midterm elections, initially focused more on the leak itself than on what it revealed. They also decried the protests that formed outside the homes of some conservative justices, accusing activists of trying to intimidate the court.

The unprecedented leak of Alito's draft opinion blew a hole in the cloak of secrecy normally shrouding the court's internal affairs. It drew harsh scrutiny from the court's critics, many of whom were already concerned about the politicization of the country's most powerful deliberative body, where justices are appointed for life.

Roberts vowed that the work of the court "will not be affected in any way" by the leak, which he described as a "betrayal" intended to "undermine the integrity of our operations."

The leak had clearly had an impact, however. Tall fencing was set up around the court building afterward, and Attorney General Merrick Garland directed the U.S. Marshals Service to "help ensure the Justices' safety."