Jefferson was not a crafter of the Constitution, he was in France when it was “crafted”, and he was not in favor of it.
James Madison and Thomas Jefferson wrote one another prolifically during the Constitutional Convention.
All of these convictions, and many more, found their way into the Virginia Plan, which Madison, in consultation with Edmund Randolph, James Wilson, Alexander Hamilton, and in his extended correspondence with Tom Jefferson in Paris,
The first amendment to the U.S. Constitution: Religious aspects
The roots of the First Amendment can be traced to a bill written by Thomas Jefferson (1743-1826) in 1777 and proposed to the Virginia Legislature in 1779. 1It guaranteed freedom of (and from) religion. After an impassioned speech by James Madison, and after some amendments, it became law in that state on 1786-JAN-16
Jefferson was pleased with the constitution, but felt it was incomplete. He pushed for legislation that would guarantee individual rights, including what he felt was the prime guarantee: freedom of and from religion. Madison promised to promote such a bill, in order to gain support for the ratification of the constitution by the State of Virginia. In 1789, the first of ten amendments were written to the constitution; they have since been known as the Bill of Rights.