The Articles of Confederation were the first national constitution of the United States, adopted by the Continental Congress in 1777 and effective from 1781 to 1789. They established a loose confederation of sovereign states united for common purposes like defense and diplomacy while preserving most powers for the individual states. The Articles created a national government with a single legislative body, the Congress of the Confederation, where each state had one vote. However, the central government had limited authority, lacking executive and judicial branches, and required unanimous consent from all states to amend the Articles. They were eventually replaced by the U.S. Constitution in 1789 to create a stronger federal government. Key features include:

• States retained sovereignty, freedom, and independence except for powers expressly delegated to Congress.
• A "firm league of friendship" was formed among states for mutual defense and welfare.
• Citizens had privileges and immunities across states, with laws and judicial proceedings recognized among states.
• Congress held powers such as declaring war, negotiating treaties, regulating currency, and establishing postal services.
• Amendments required unanimous agreement by all states.
• The Articles emphasized a perpetual union but created a weak central government focused mainly on coordinating states rather than governing directly.

Thus, the Articles of Confederation was more a treaty among states than a cohesive, centralized national government.