Final answer:
James Madison did not hold the title of president, treasurer, secretary, or chairman at the Constitutional Convention; instead, he earned the moniker 'Father of the Constitution' for his critical contributions.
Step-by-step explanation:
James Madison became the 'Father of the Constitution' due to his pivotal role at the Constitutional Convention. While the delegates elected George Washington to preside over the convention as its president, Madison was instrumental in crafting the framework of the United States government. Renowned for his authorship of the Virginia Plan, contributions to the Federalist Papers, and later efforts in drafting the Bill of Rights, Madison's role was central in shaping American governance, though he did not hold a titled leadership role such as treasurer, secretary, or chairman at the convention itself.