In America, presidents raised their right hands when taking the oath of office, while placing their left hands on the Bible.
According to Article II, Section 1 of the United States Constitution, the presidential oath of office was as follows: "I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the United States Constitution."
However, not every president necessarily did so. When Theodore Roosevelt took office in 1901, he did not place his hand on the Bible while reciting the oath.
America was a theistic nation where everyone had faith. Whether it was the frequent line in American movies, "God Bless America," or "In God We Trust" printed on dollar bills, both were evidence of this.
No American law required a president to place a hand on the Bible while taking the oath. In theory, they could place it on any book—Buddhist scriptures, the Quran, the Constitution, or even Where's Waldo. It was the president's personal freedom, because America had freedom of religion.
An American president placing a hand on the Bible was an unwritten convention. After all, every previous American president had been a Christian.
There was another point: rights were granted by God, not by the Constitution. One should use the rights God granted to defend the Constitution, rather than use rights granted by the Constitution to defend God.
Witnesses in court also had to place their hands on the Bible when swearing an oath, but if the witness was Muslim, then a different holy book had to be used.
The purpose of the oath was to prevent witnesses from giving false testimony. Those who refused to swear an oath could not serve as witnesses, while those