After declaring independence from Britain in 1776, the thirteen states created a permanent alliance to coordinate American efforts to win the Revolutionary War. This alliance, the United States, was to be governed according to the Articles of Confederation, which was more of a treaty between independent countries than a national constitution. The Articles were adopted by the Second Continental Congress in 1777 but not finally ratified by all states until 1781. During the Confederation Period, the United States was essentially a federation of independent republics, with the Articles guaranteeing state sovereignty and independence. The Confederation was governed by the Congress of the Confederation, a unicameral legislature whose members were chosen by the state legislatures and in which each state cast a single vote. Congress was given a limited set of powers, mainly in the area of waging war and foreign affairs. It could not levy taxes or tariffs, and it could only request money from the states, with no power to force delinquent states to pay. Since the Articles could only be amended by a unanimous vote of the states, any state had effective veto power over any proposed change. A super majority (nine of thirteen state delegations) was required for Congress to pass major legislation such as declaring war, making treaties, or borrowing money. The Confederation had no executive or judicial branches, which meant the Confederation government lacked effective means to enforce its own laws and treaties against state non-compliance. It soon became evident to nearly all that the Confederation government, as originally organized, was inadequate for managing the various problems confronting the United States.