b) 1788

The U.S. Constitution was fully ratified in 1788, marking a new era in American governance. The ratification process, requiring the approval of nine out of thirteen states, was completed when New Hampshire became the ninth state to ratify the Constitution. This momentous event signified the adoption of a new framework for the federal government, replacing the Articles of Confederation. The ratification of the Constitution in 1788 was a foundational moment in U.S. history, establishing the principles and structure of government that continue to guide the nation.