In 1777 the 13 colonies that had declared independence from Great Britain one year earlier (July 1776) agreed to the formation of a confederation of states under the Articles of Confederation, with an extremely limited central government. A new national frame of government came into force in 1789, when the current U.S. Constitution replaced the Articles. This constitution incorporates the doctrine of the separation of powers, whereby the federal government is divided into three branches, as well as concepts of federalism, describing the rights and responsibilities of state governments and of the states in relationship to the federal government.