What year was the U.S. Constitution ratified?

The U.S. Constitution was ratified in 1788. This year is significant because it marks the conclusion of a process that began with the Constitutional Convention in Philadelphia in 1787, where the document was drafted. After its drafting, the Constitution needed to be ratified by nine of the thirteen states to become effective. The ratification process took place over the course of several months throughout 1788, and the Constitution officially took effect on March 4, 1789, after nine states had ratified it. Understanding this timeline is crucial for grasping the establishment of the United States' foundational governing document and the evolution of its federal system, which transitioned from the Articles of Confederation to a stronger centralized framework.