Well, it's KINDA true.
Calling New England Universalists and Deists "Christians" is really stretching the definition.
I am not going to go through the history manuals, but sure - you had Jefferson and Franklin who were Deists, but as you noted the vast majority of the people who founded this Country AND the people who we call the Founding Fathers (e.g., Patrick Henry, George Washington, John Adams, etc) were Christians.
“The general principles on which the fathers achieved independence were the general principles of Christianity.”
- John Adams
“...the confusions that are and have been among the nations may be overruled by the promoting and speedily bringing in the holy and happy period when the kingdoms of our Lord and Savior Jesus Christ may be everywhere established, and the people willingly bow to the scepter of Him who is the Prince of Peace.”
_ Samuel Adams
“...confess before God their aggravated transgressions and to implore His pardon and forgiveness through the merits and mediation of Jesus Christ”
- Josiah Bartlett
“...the Father, the Son, and the Holy Ghost – be ascribed all honor and dominion, forevermore – Amen”
- Gunning Bedford
“Let us enter on this important business under the idea that we are Christians on whom the eyes of the world are now turned”
- Elias Boudinot
“...don’t forget to be a Christian”
_ Jacob Broom
“Grateful to Almighty God for the blessings which, through Jesus Christ Our Lord, He had conferred on my beloved country in her emancipation and on myself in permitting me, under circumstances of mercy, to live to the age of 89 years, and to survive the fiftieth year of independence, adopted by Congress on the 4th of July 1776, which I originally subscribed on the 2d day of August of the same year and of which I am now the last surviving signer.”
- Charles Carroll
“Rendering thanks to my Creator for my existence and station among His works, for my birth in a country enlightened by the Gospel and enjoying freedom, and for all His other kindnesses, to Him I resign myself, humbly confiding in His goodness and in His mercy through Jesus Christ for the events of eternity”
- John Dickinson
“I resign my soul into the hands of the Almighty Who gave it, in humble hopes of His mercy through our Savior Jesus Christ.”
- Gabriel Duvall
“s to Jesus of Nazareth, my opinion of whom you particularly desire, I think the system of morals and His religion as He left them to us, the best the world ever saw or is likely to see.
- Benjamin Franklin
“...let us contemplate the blessings which have flowed from the unlimited grave and favor of offended Deity, that we are still permitted to enjoy the first of Heaven’s blessings: the Gospel of Jesus Christ.”
- Elbridge Gerry
“...a mes¬sage was sent informing me of the sad event, accompanied by a request from General Hamilton that I would come to him for the purpose of administering the Holy Communion.”
- Rev. Benjamin Moore, speaking of Alexander Hamilton’s request in the hours after being shot by Aaron Burr. Hamiton’s death cut short Hamilton his proposal for the creation of the Christian Constitutional Society, and listed two goals for its formation: first, the support of the Christian religion; and second, the support of the Constitution of the United States.
He called on the entire State of Massachusetts to pray “that universal happiness may be established in the world [and] that all may bow to the scepter of our Lord Jesus Christ, and the whole earth be filled with His glory.”
- John Hancock
“Being a Christian… is a character which I prize far above all this world has or can boast.”
- Patrick Henry
“...we may obtain forgiveness through the merits and mediation of our Lord and Savior Jesus Christ”
- Samuel Huntington
“Mercy and grace and favor did come by Jesus Christ, and also that truth which verified the promises and predictions concerning Him and which exposed and corrected the various errors which had been imbibed respecting the Supreme Being, His attributes, laws, and dispensations.”
- John Jay
“I am a real Christian – that is to say, a disciple of the doctrines of Jesus Christ.”
- Thomas Jefferson
“I give and bequeath my soul to Almighty God that gave it me, hoping that through the meritorious death and passion of our Savior and Redeemer Jesus Christ to receive absolution and remission for all my sins.”
- George Mason
“You do well to wish to learn our arts and ways of life, and above all, the religion of Jesus Christ.”
- George Washington
There’s more if you care to learn:
http://www.wallbuilders.com/libissuesarticles.asp?id=8755#FN1