I do believe this gentleman is mistaken. The Founding Fathers, including George Washington, Thomas Jefferson, Samuel Adams, Benjamin Franklin, John Adams, John Hancock, James Madison, and Alexander Hamilton were not atheists at all. A list of their religious affiliations indicates that 88 were either Episcopalian or Anglican, 30 were Presbyterian, and 27 were members of independent Protestant congregations. Another 7 were Quakers, 6 with the Dutch or German Reformed Church, 5 Lutherans, to go along with 3 Catholics, 3 Huguenots, and 3 Unitarians. 2 were part of the Methodist Church, and there was a Calvinist.  

Even Thomas Jefferson, the principle writer of the Declaration of Independence, was part of the Episcopalian Church and throughout his life claimed to be a follower of Jesus Christ. 

In short, it would appear that your submission is totally fabricated.