The first Constitution of the United States. The Continental Congress adopted these "Articles of Confederation and Perpetual Union Between the States" in 1777. Under the articles, each state "retain[ed] its sovereignty, freedom, and independence." It took until 1781 for all 13 states to ratify the Articles. Perceived weaknesses in this confederation style of union led delegates at the Constitutional Convention in Philadelphia to abandon the Articles in 1787 in favor of the current United States Constitution.