Philadelphia hosted the 1787 Constitutional Convention connected to the founding story behind America250. Delegates met there from May 25 to September 17, 1787, to revise the Articles of Confederation.
The convention soon moved beyond simple revision and drafted an entirely new Constitution. George Washington presided, while figures including James Madison, Benjamin Franklin, Alexander Hamilton, and Gouverneur Morris played important roles in the debates and drafting.
Philadelphia had already been central to the independence movement. The Second Continental Congress met there when it adopted the Declaration of Independence in 1776, making the city a major setting for both independence and constitutional government.
The convention’s work did not automatically make the Constitution law. The document required ratification by nine states. After the ninth state approved it in 1788, the new federal government began operating in 1789.