Which 1787 Philadelphia convention drafted the U.S. Constitution?

The 1787 Philadelphia convention that drafted the U.S. Constitution was the Constitutional Convention.

The meeting began after the Articles of Confederation proved too weak to manage national finances, interstate disputes, trade, and defense. Congress had authorized the gathering to revise the Articles, but delegates soon decided that a completely new framework of government was needed.

The convention met from May 25 to September 17, 1787, in the Pennsylvania State House, later renamed Independence Hall. George Washington presided, while James Madison’s ideas helped shape the discussions. Delegates debated plans for representation, executive power, the federal judiciary, and the relationship between national and state governments.

Twelve states sent delegates; Rhode Island declined to participate. Fifty-five delegates attended at some point, and 39 signed the proposed Constitution on September 17. The convention itself did not make the Constitution effective: state conventions had to ratify it afterward. The Constitution became operative in 1789 after the required ratifications.