Final answer:
The Intolerable Acts were the English laws that prompted the First Continental Congress to write a letter to King George III and boycott English goods.
Step-by-step explanation:
The English law that prompted the First Continental Congress to write a letter to King George III and boycott English goods when he refused to repeal the law is the Intolerable Acts. The Intolerable Acts, also known as the Coercive Acts, were a series of punitive laws passed by Parliament in response to the Boston Tea Party. These acts closed the port of Boston, limited colonial assemblies, and disbanded town meetings, leading to increased tension between Great Britain and the American colonies.