What religion was the United States of America built upon?

The United States is not founded or built on any particular religion. A theocracy is a system of government in which society is governed by a religious doctrine or clergy, but the U.S. is a secular republic. The authority of the United States government is not derived from an appeal to a religion—it is derived from the Constitution itself. While the founding fathers on a personal level may have held religious convictions which influenced policy-making decisions, the First Amendment to the United States Constitution establishes a clear separation between church and state. The religious elements of the civic culture in the US did not appear with the birth of the nation. “Under God” was not added to the Pledge of Allegiance until 1954 and “In God We Trust” didn’t appear on money consistently until 1957. Many religions have made a deep impact on the fabric of American culture. However, America’s independence marked the break away from religious monarchical rule and toward government based on secular ideas.