As President, Obama, has restated this numerous times including in 2008, during his first visit to a Muslim nation in 2009 and again numerous times in 2010.
According to Wikipedia (2008) 78.5% of our population call themselves Christians. Non-christian religions make up 5.5% and 15% claims no religious belief.
Our history shows we were founded on Christianity.
First Supreme Court Justice John Jay (served from 1789 to 1795)
“Providence has given to our people the choice of their rulers, and it is the duty, as well as the priveledge and interest of our Christian nation to select and prefer Christians for their rulers.”
Supreme Court Justice Joseph Story (served from 1812 to 1845)
“I verily believe Christianity necessary to the support of civil society. One of the beautiful boasts of our municipal jurisprudence is that Christianity is a part of the Common Law. There never has been a period in which the Common Law did not recognize Christianity as lying its foundations.”
Supreme Court Justice David Brewer (served from 1890 to 1910) said:
“This is a religious people. This is historically true. From the discovery of this continent to the present hour, there is a single voice making this affirmation … We find everywhere a clear recognition of the same truth … These, and many other matters which might be noticed, add a volume of unofficial declarations to the mass of organic utterances that this is a Christian nation.“
John Quincy Adams (6th President of the United States)
“The greatest glory of the American Revolution was this: It connected in one indissoluble bond, the principles of civil government with the principles of Christianity.”
From the early colonial days, when English and German settlers came in search of religious freedom, America has been profoundly influenced by religion. That influence continues in American culture, social life, and politics.
Several of the original Thirteen Colonies were established by settlers who wished to practice their own religion without discrimination: the Massachusetts Bay Colony was established by English Puritans (Congregationalists), Pennsylvania by British Quarters, Maryland by English Catholics, and Virginia by English Anglicans.