Established by the United States Constitution, the Supreme Court began to take shape with the passage of the Judiciary Act of 1789 and its first assembly began in 1790.
The Constitution elaborated neither the exact powers and prerogatives of the Supreme Court nor the organization of the Judicial Branch as a whole. Thus, it was left to Congress and to the Justices of the Court through their decisions to develop the Federal Judiciary and a body of Federal law. [https://www.supremecourt.gov/about/institution.aspx]
