Washington as Statesman at the Constitutional Convention Painting by Junius Brutus Stearns (1856). Gift of Edgar William and Bernice Chrysler Garbisch. Courtsey of Virginia Museum of Fine Arts
Madison understood what Staurt Leiberger argues that "Washington's participation was indispensable to the convention's success because it guaranteed a large turnout of dedicated men and added legitimacy." Before coming to the convention, Washington realized that reforming the Articles of Confederation would not be enough, and Washington was able to rely on Madison's friendship to exchange ideas. Washington arrived in Philadelphia on May 13, and he worked with his fellow Virginia delegates on the Virginia Plan.
Reference: Stuart Leibiger, Founding Friendship: George Washingtin, James Madison, and the Creation of the American Republic 68