Who were the committee of correspondence? how were they seen as a shadow government?

The committees of correspondence were shadow governments organized by the Patriot leaders of the Thirteen Colonies on the eve of the American Revolution. They coordinated responses to England and shared their plans; by 1773 they had emerged as shadow governments, superseding the colonial legislature and royal officials. The Maryland Committee of Correspondence was instrumental in setting up the First Continental Congress, which met in Philadelphia. These served an important role in the Revolution, by disseminating the colonial interpretation of British actions between the colonies and to foreign governments. The committees of correspondence rallied opposition on common causes and established plans for collective action, and so the group of committees was the beginning of what later became a formal political union among the colonies.