Unbiased:

To call David Barton a ‘Historian’ is very generous.  His only college-level education is a BA in Religious Education from Oral Roberts University.  He has many times allied himself with racist supporters of the ‘Christian Identity’ movement, and has been caught several times misquoting and misrepresenting statements of the founding fathers, and misrepresenting court decisions.  You ask for an ‘objective mind’, yet you cite Barton?  This may suffice amongst believers, but not to those who ask for honesty and integrity.  These refutations of Barton are not hard to find.  Barton and his ilk like to say that seperation of church and state originated in 1947, yet this date is closer to when the christian movement began to assert more influence in government and began to attempt to revise history. “In God we trust” didnt begin to appear on coins until 1864, not made law until 1908, and not added to paper currency until 1954.  “under god” was added to the pledge of allegiance in 1953. To go back a little further than the 1940s, check the ACTUAL quotes from some early american figures:
 
“I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should ‘make no law respecting an establishment of religion, or prohibiting the free exercise thereof,’ thus building a wall of separation between Church & State.” THomas Jefferson 1802 – The 1947 supreme court case you refer to was quoting Jefferson.. from 1802

“As the Government of the United States of America is not, in any sense, founded on the Christian religion; as it has in itself no character of enmity against the laws, religion, or tranquility, of Mussulmen; and, as the said States never entered into any war, or act of hostility against any Mahometan nation, it is declared by the parties, that no pretext arising from religious opinions, shall ever produce an interruption of the harmony existing between the two countries.” 1797, Treaty of Tripoli, article 11

“A hedge or wall of separation between the garden of the church and the wilderness of the world” 1644- Roger Williams, theologian, founder of the first Baptist Church

You’ll find that 1644 was just a wee bit before 1947. I await any response.
Rob

 They are just America’s Taliban.

How disturbing  - religion and fanatics like these people have murdered millions of people in the name of their god – learn your history and see it is all about power, ignorance, fear and greed.  Life is for living – not brainwashing kids into a system that benefits them and then trying to rule the world for their own toxic beliefs.  Down with Religion – up with living life on earth in peace. 
Down with the Fed, IMF and World Bank too – the corrupt Fractional Reserve Monetary System only benefits the greedy billionaires while hundreds of millions starve to death and the middle class get sucked into endless debt.  Open your eyes.