What is the name of the first Constitution of the United States, ratified by the original 13 colonies?

The first Constitution of the United States, ratified by the original 13 colonies, is known as the Articles of Confederation. This document was enacted in 1781 and served as the initial governing framework for the newly independent states. It established a confederation of sovereign states and a weak central government, which was primarily due to the colonists' apprehensions about creating a powerful national government similar to British rule.

The Articles allowed for a limited federal authority, which made it challenging to enforce laws, levy taxes, or regulate commerce effectively. This lack of a strong central authority prompted discussions that eventually led to the drafting of the more robust Constitution of 1787, which replaced the Articles of Confederation due to various weaknesses identified over time.

The Bill of Rights refers to the first ten amendments to the Constitution and does not represent the initial governing document of the United States. The Magna Carta, while a historic document influencing American legal principles, predates the United States and played a role in establishing constitutional governance in England rather than serving as the constitution for the U.S. The Constitution of 1787 succeeded the Articles but is not the first constitution itself. Thus, the Articles of Confederation is the correct response to the question.