the supreme court of the united states is the highest ranking judicial body in the united states. established by article iii of the constitution, the detailed structure of the court was laid down by the 1st united states congress in 1789. congress, through the judiciary act of 1789, specified the court's original and appellate jurisdiction, created 13 judicial districts, and fixed the initial size of the supreme court at six members. the number of justices on the court changed several times over the ensuing 80 years.