What was the first written constitution of the United States called?

The Articles of Confederation were the first written constitution of the United States.

The Second Continental Congress adopted the Articles on November 15, 1777, but they did not take effect until March 1, 1781, after all 13 states ratified them. The document created a “firm league of friendship” among the states and gave Congress authority over diplomacy, war, and western territories.

Under the Articles, the national government had no separate executive branch or national judiciary. Congress also lacked power to impose taxes directly, regulate interstate commerce, or force states to supply money and troops. Each state retained substantial sovereignty, which made national decisions difficult to enforce.

The Confederation Congress nevertheless achieved important results. It negotiated the Treaty of Paris, passed the Land Ordinance of 1785, and enacted the Northwest Ordinance of 1787. Financial problems, interstate disputes, and concerns about national weakness eventually encouraged the Philadelphia Convention to replace the Articles with the Constitution in 1787.