Who led the meeting to create the Constitution?

George Washington was the presiding officer of the "Federal Convention" as it was known then, but has now come to be known as the Constitutional Convention.

As far as ideological leadership goes, James Madison had the most active role in guiding the various discussions through to conclusion. Gouverneur Morris hand wrote most of the Constitution after 23 resolves had been agreed to and he condensed them down to 7 and basically the final form of the Constitution.