The Constitutional Convention Frames a New Government
Fifty-five delegates spend a Philadelphia summer replacing a failing government
Quick facts
- Convention
- Philadelphia, May to September 1787
- Delegates attending
- 55 of 74 appointed
- Signed
- September 17, 1787
- In effect
- 1789, after ratification by the states
What happened
Under the Articles of Confederation, the first national government of the independent states, the central government was too weak to regulate commerce, raise reliable revenue, or hold the union together. In the summer of 1787, delegates gathered at the Pennsylvania State House in Philadelphia to fix it. Seventy-four delegates were appointed and 55 attended, with George Washington presiding and James Madison among the driving forces. Rather than amend the Articles, they wrote an entirely new Constitution, creating a stronger federal government with three branches and a system of checks and balances, and compromising bitterly over representation and over slavery. They signed the finished document on September 17, 1787, and sent it to the states. Nine states had to ratify it for it to take effect, which they did by 1788, and the new government began in 1789.
Why it matters
The Constitution is the framework the United States still governs itself by, the oldest written national constitution in continuous use. The compromises made in that Philadelphia room, including the ones that protected slavery and counted enslaved people as three-fifths of a person for representation, shaped American politics for generations and left conflicts that would eventually be settled only by civil war.
How we know
The Constitution itself survives with its 39 signatures, and the convention's debates are known from Madison's detailed notes and from the ratification records of the individual states.
Sources
- National Archives. A More Perfect Union: The Creation of the U.S. Constitution · Primary source (author-declared)archives.gov · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- Office of the Historian, U.S. Department of State. Convention and Ratification, 1787-1789 · Reputable sourcehistory.state.gov · The domain "history.state.gov" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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Part of a timelineHistory of the United States32 events · A hundred English colonists on a swampy island, a constitution argued out over one Philadelphia summer, a country that doubled its size for four cents an acre and fought a civil war over who counted as free, and the superpower that came out the other sideView all →