Jan. 22, 1973. In Roe v. Wade, the court for the first time legalized abortion nationwide. The court based its 7-2 ruling on a woman's constitutional right to privacy.

Jan. 22, 1973. In Doe v. Bolton, the court struck down by a 7-2 vote restrictions on facilities that could be used to perform abortions. The decision gave rise to a new kind of medical facility, the abortion clinic.

July 1, 1976. In Planned Parenthood v. Danforth, the court, by a 6-3 vote, said states cannot give husbands veto power over their pregnant wives' decision to abort their pregnancies. By a 5-4 vote, the court said parents of minor, unwed girls cannot be given an absolute veto over abortions.

Jan. 9, 1979. In Colautti v. Franklin, reached by a 6-3 vote, the court reaffirmed its intention to give doctors broad discretion in determining the timing of ``fetal viability'' - when a fetus can live outside the mother's womb. The justices said states may seek to protect a fetus that has reached viability, but the determination is up to doctors, not courts or legislatures.

June 15, 1983. In three decisions led by one called City of Akron v. Akron Center for Reproductive Health, the court said, 6-3, that states and local communities may not require all abortions beyond the first trimester be performed in a hospital.

June 11, 1986. In Thornburgh v. American College of Obstetricians and Gynecologists, the court struck down, 5-4, Pennsylvania abortion regulations that would have required doctors to inform women seeking abortions about potential risks and about available medical assistance benefits for prenatal care and childbirth.

July 3, 1989. In a series of split votes in Webster v. Reproductive Health Services, the court provided states with new authority to limit a woman's right to abortion but stopped short of reversing its 1973 decision legalizing abortion. The justices allowed Missouri to restrict the use of public money, medical personnel or facilities in performing abortion procedures. Also upheld was a requirement that doctors determine, when possible, whether a fetus at least 20 weeks old is capable of surviving outside the womb, by testing lung capacity and conducting other tests.

June 29, 1992. In its most important abortion ruling since 1973, the court voted 5-4 to uphold the core of its Roe v. Wade decision and ban states from outlawing most abortions. But, by a 7-2 vote, the court said states may raise new hurdles for women seeking to end their pregnancies. The court's decision in Planned Parenthood v. Casey abandoned the trimester-by-trimester approach of its 1973 ruling and adopted a new test - abortion regulations will not be allowed if they represent an ``undue burden'' on women's constitutional right.

June 28, 2000. In Stenberg v. Carhart, the court voted 5-4 to strike down Nebraska's ``partial-birth'' abortion law because it imposed an ``undue burden'' on women's right to end their pregnancies. The court said the law, similar to those in 29 other states, lacked an exemption to preserve women's health and could have been used to ban more than one abortion method.