<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Thirteen Colonies were a group of British colonies on the east coast of North America founded in the 17th and 18th centuries that declared independence in 1776 and formed the United States of America . The Thirteen Colonies had very similar political, constitutional, and legal systems, and were dominated by Protestant English - speakers . They were part of Britain's possessions in the New World, which also included colonies in Canada and the Caribbean, as well as East and West Florida . </P> <P> In the 18th century, the British government operated its colonies under a policy of mercantilism, in which the central government administered its possessions for the economic benefit of the mother country . However, the Thirteen Colonies had a high degree of self - governance and active local elections, and resisted London's demands for more control . In the 1750s, the colonies began collaborating with one another instead of dealing directly with Britain . These inter-colonial activities cultivated a sense of shared American identity and led to calls for protection of the colonists' "Rights as Englishmen", especially the principle of "no taxation without representation". Grievances with the British government led to the American Revolution, in which the colonies collaborated in forming a Continental Congress which declared independence in 1776 and fought the American Revolutionary War (1775--83) with the aid of France, the Dutch Republic, and Spain . </P>

When did the 13 colonies became part of the united states