Who was a key figure at the Constitutional Convention?

Several key figures shaped the Constitutional Convention that met in Philadelphia from May 25 to September 17, 1787, including George Washington of Virginia, James Madison of Virginia, and Benjamin Franklin of Pennsylvania, along with Alexander Hamilton of New York, Roger Sherman and Oliver Ellsworth of Connecticut, James Wilson and Gouverneur Morris of Pennsylvania, John Rutledge and Charles Pinckney of South Carolina, George Mason and Edmund Randolph of Virginia, and William Paterson of New Jersey. George Washington served as the convention's presiding officer, elected unanimously on the opening day. Although he rarely spoke during debate, his prestige as the victorious commander of the Continental Army gave the convention legitimacy and allowed it to proceed despite the controversial decision to scrap the Articles of Confederation rather than merely revise them. Many delegates believed the convention would have failed without his quiet authority.

James Madison of Virginia is often called the Father of the Constitution. He arrived in Philadelphia early to draft the Virginia Plan, which Edmund Randolph introduced on May 29, 1787 and which framed the convention's agenda. Madison kept careful daily notes that became the chief record of the proceedings. He emerged as the principal theorist, drafted many of the key passages, and helped sell the result to the states through The Federalist Papers. He was 36 years old.

Benjamin Franklin of Pennsylvania, at age 81 the elder statesman, lent the convention his prestige and frequently advanced compromise. He proposed that sessions begin with prayer (the suggestion was not adopted), supported the Connecticut Compromise on representation, and on the final day delivered through James Wilson a closing speech urging unanimous signing despite imperfect satisfaction with the result.

Other major figures played essential roles. Alexander Hamilton represented New York but was usually outvoted by his Anti-Federalist colleagues; he later wrote 51 of the 85 Federalist Papers. Roger Sherman and Oliver Ellsworth of Connecticut brokered the Great Compromise of July 16, 1787 that resolved the deadlock between large and small states. James Wilson of Pennsylvania helped design the executive branch and the Three-Fifths Compromise. Gouverneur Morris of Pennsylvania wrote the final language of the Constitution including the famous preamble beginning "We the People." George Mason of Virginia drafted the Virginia Declaration of Rights of June 12, 1776 that influenced the later federal Bill of Rights, but refused to sign the Constitution because it lacked a Bill of Rights. Edmund Randolph also refused to sign but later supported ratification. The convention had 55 delegates total, of whom 39 signed on September 17, 1787.