What law created the original federal court system?

Answer 1

The United States Judiciary Act of 1789 (1 Stat. 73) was a landmark statute adopted on September 24, 1789 in the first session of the First United States Congress establishing the U.S. federal judiciary. Article III of the United States Constitution created the Supreme Court and gave Congress the power to establish inferior courts. It made no provision, though, for the composition or procedures of any of the courts, leaving this to Congress to decide.