An Act to regulate the Time and Manner of administering certain Oaths was the first law passed by the United States Congress after the ratification of the U.S. Constitution. It was signed by President George Washington on June 1, 1789, and parts of it remain in effect to this day
Good question it is importantly because If no one knew then it would be chaos
Ordinance Is a law or decree by a municipality. Meanwhile precedent a court decision that is considered as authority for deciding subsequent cases involving identical or similar fact, or similar legal issues.