James Madison is known as the Father of the Constitution because of his pivotal role in the document's drafting as well as its ratification. Madison also drafted the first 10 amendments -- the Bill of Rights.
Who actually wrote the Constitution of the United States?
The easiest answer to the question of who wrote the Constitution is James Madison, who drafted the document after the Constitutional Convention of 1787.
When was the Constitution written and who wrote it?
The Constitution was written during the summer of 1787 in Philadelphia, Pennsylvania, by 55 delegates to a Constitutional Convention that was called ostensibly to amend the Articles of Confederation (1781–89), the country's first written constitution.