Let’s dive into a bit of legal history. When did the US set up its first court system?
If you mean the federal system, it starts with the Judiciary Act of 1789, and the Supreme Court first sat on Feb 2, 1790; small caveat: under the Continental Congress there was a ‘Court of Appeals in Cases of Capture’ as early as 1780. I usually confirm dates with the National Archives page on the Act (https://www.archives.gov/milestone-documents/judiciary-act) — are you after the federal start or the earlier revolutionary setup?