On Friday, June 24, the Supreme Court ruled to overturn their decision from their 1973 decision in "Roe v Wade." Roe established that a woman had a Constitutionally-protected right to abortion as long as strict time-based guidelines were followed. Roe essentially established a uniform set of guidelines that all states had to follow, replacing the patchwork of rules and laws that had been in place up to that point.
With the overturning of the case, the majority ruled that the Constitution doesn't explicitly mention or guarantee such a right to abortion--consistent with the philosophy of "originalism," a way of looking at the Constitution from the point of view of the original writers of the document.
Now, a patchwork of state laws will take the place of the national standard and we've already seen states move to enforce existing laws that restrict abortions or move to make them illegal altogether.
A very nice summary of what's next is below: