[Political historian here] Each colony was settled by a different group of people: for example, the Puritans in Massachusetts Bay, the Dutch in New Amsterdam (New York); mercantile companies such as the Virginia Company. Each was settled for different reasons. Each had a charter outlining colonial government (which varied), which made each colony independently a “province” of the British Empire. The only government above the one in Boston, or Jamestown, or New York was Parliament and the King.

In May, 1643, Massachusetts, Connecticut, Plymouth and New Haven colonies formed the short-lived “United Colonies of New England”, commonly known as the New England Confederation. This was primary a mutual defense pact. It dissolved in the 1680s, during the reign of King James II. [Rhode Island was excluded because (a) everyone hated the religious freedom there and (b) it didn’t matter, as Connecticut and Massachusetts Bay surrounded Rhode Island.]

James II, for various reasons including smuggling, decided to merge all the colonies (except Pennsylvania) into the “Domininon of New England,” patterned after New Spain. Edmund Andros was appointed Governor, but the geography was too large to be governed by one person. New Englanders hated it, as the resented their loss of political freedom. When James was overthrown by his daughter Mary and her husband William of Orange in the Glorious Revolution, colonists overthrew the Dominion. Andros was arrested in Boston, and the elderly Simon Bradstreet was appointed Provisional Governor while Mass. Bay sent a delegation to restore the charter.

The idea of colonial cooperation and unity surfaced again during the French and Indian War, when a colonial assembly proposed the Albany Plan of Union, but it was rejected by Parliament.

Events before the Revolution drove the colonies together in economic and political self-interest, and so the notion of a united political structure came to the fore. The Articles of Confederation were the first constitution, and the truest expression of REvolutional thought, but they did not work well and the Constution of 1787 replaced the Articles.