Maryland was the last of the original 13 states to ratify the Articles of Confederation.
Maryland delayed ratification because it objected to western land claims held by states such as Virginia. Maryland wanted those territories transferred to the Union rather than allowing individual states to expand their borders and power.
The dispute lasted for several years while the Continental Congress operated under the Articles as a de facto governing framework. Maryland’s legislature finally authorized ratification on February 2, 1781. Congress was informed of the decision on March 1, 1781, when the Articles officially took effect.
Maryland’s decision helped establish a clearer national union and permitted Congress to administer western lands. The delay is easy to confuse with the later ratification of the U.S. Constitution, which Maryland approved in 1788. The Articles were ultimately replaced by that Constitution in 1789.