In Gore Vidal's "The Decline and Fall of the American Empire," he discusses the historical separation of church and state in the United States. He notes that this division was originally clear-cut in the Republic's formation, emphasizing a foundation free from religious influence in government matters.

However, Vidal points out that this separation has been challenged over time, particularly highlighting the 1950s when the phrase "In God We Trust" was added to U.S. currency. He argues that this move violated the First Amendment's principles, illustrating the persistent struggle between secular governance and religious influence in American society.