Maryland was the final state to ratify the Articles of Confederation.
The Articles served as the first constitution of the United States during and immediately after the Revolutionary War. Congress approved them for submission to the states in November 1777, but unanimous ratification took years. Maryland withheld approval largely because it wanted states with western land claims, especially Virginia, to transfer those claims to the Union.
Maryland finally ratified the Articles on February 2, 1781. Congress was informed of the decision in March, and the Articles came into force on March 1, 1781. This made the document the operating frame of government for the United States. The Articles created a loose union with a weak central authority, no separate executive, and limited power to tax. Their shortcomings helped lead to the Constitutional Convention and the stronger federal system established in 1789.