Answer:
By forming intercolonial Committees of Correspondence
Step-by-step explanation:
The intercolonial Committees of Correspondence, which started in Boston and led by a certain Samuel Adams had the purpose of spreading resistance to British rule and policies. This is carried out by the exchange of letters between the colonies which include ideas, information, and combined actions to take against the British rule.
Hence, in this case, the protests and resistance to British policy spread beyond Boston "by forming intercolonial Committees of Correspondence."