The U.S. Supreme Court was established by Article Three of the U.S. Constitution, which took effect in March 1789. The Constitution granted the Supreme Court ultimate jurisdiction over all laws, especially those in which constitutionality was at issue. The court was also designated to rule on cases concerning treaties of the United States, foreign diplomats, admiralty practice, and maritime jurisdiction.
In September 1789, the Judiciary Act was passed, implementing Article Three by providing for six justices who would serve on the court for life. The same day, President George Washington appointed John Jay to preside as chief justice, and John Rutledge of South Carolina, William Cushing of Massachusetts, John Blair of Virginia, Robert Harrison of Maryland, and James Wilson of Pennsylvania to serve as associate justices. Two days later, all six appointments were confirmed by the U.S. Senate.
The Supreme Court later grew into arguably the most powerful judicial body in the world in terms of its central place in the U.S. political order. In times of constitutional crisis, for better or worse, it always played a definitive role in resolving the great issues of the time.