The tradition of using a Bible during the swearing-in goes back to the very first inauguration, but not all Presidents have used one.

Trump was sworn in as the 47th president of the United States on Monday, taking the oath without placing his hand on the Bible

Some presidents did not use a Bible to take the oath of office, including Theodore Roosevelt, who did not use anything when he was sworn into office in 1901, and John Quincy Adams, who chose a legal book for his 1825 swearing-in, to signify his responsibility to uphold the U.S. constitutional law.