James Madison has been denominated the Father of the U.S. Constitution; however this is because Madison was appointed by the Constitutional Convention as its recording secretary. His Notes on the Constitutional Convention are the only authentic evidence available as to the debate within the convention as the first order of the convention, after the election of George Washington as President, was to keep its proceedings secret.
As to the actual writing of the Constitution, following the adoption of its major proposals, it was referred to a Committee on Style and Arrangement on September 8, 1787. The members of that Committee were James Madison of Virginia, William Johnson of Connecticut, Governeur Morris of Pennsylvania, Rufus King of Massachusetts, and Alexander Hamilton of New York. The committee delivered its final report and draft on September 12, 1787. The draft of the committee with very minor provisions is the Constitution as it was adopted and ratified.