The Judiciary Act of 1789 is passed by Congress and signed by President George Washington, establishing the Supreme Court of the United States as a tribunal made up of six justices who were to serve on the court until death or retirement. That day, President Washington nominated John Jay to preside as chief justice, and John Rutledge, William Cushing, John Blair, Robert Harrison and James Wilson to be associate justices. On September 26, all six appointments were confirmed by the U.S. Senate.

READ MORE: Why Do 9 Justices Serve on the Supreme Court?

The U.S. Supreme Court was established by Article 3 of the U.S. Constitution. The Constitution granted the Supreme Court ultimate jurisdiction over all laws, especially those in which their constitutionality was at issue. The high court was also designated to oversee cases concerning treaties of the United States, foreign diplomats, admiralty practice and maritime jurisdiction. On February 1, 1790, the first session of the U.S. Supreme Court was held in New York City’s Royal Exchange Building.

The U.S. Supreme Court grew into the most important judicial body in the world in terms of its central place in the American political order. According to the Constitution, the size of the court is set by Congress, and the number of justices varied during the 19th century before stabilizing in 1869 at nine. This number, however, can be changed at any time by Congress. In times of constitutional crisis, the nation’s highest court has always played a definitive role in resolving, for better or worse, the great issues of the time.

READ MORE: 7 Things You Might Not Know About the U.S. Supreme Court