They say we became an independent nation in 1776. That is when the Declaration of Independence was signed. Based on this likely scenario, we are now 241 years old. For all those years the US was not one nation under God. Even the U.S. Founding Fathers fell into three religious categories of Gods: some had left their Judeo-Christian heritages and become advocates of the Enlightenment 

religion of nature and reason called "Deism".

It wasn't until1954, at President Dwight D. Eisenhower's request that “under God” be added, making the pledge read: I pledge allegiance to the flag of the United States of America and to the Republic for which it stands, one nation under God, indivisible, with liberty and justice for all. Although that phrase was added it carried no reason-centred Enlightenment to go against the tradition 

of racism.

All white men with no monolithic beliefs. But uncharacteristically the slave owners all believed in Jesus. Was it because they got their divine approval from a silent Jesus? Even today the term " one nation under God" is a phrase we haven't accomplished in acts and character because we haven't determined what God it is.