At noon on January 20th, Donald Trump will repeat 35 words and become president of the United States of America. Where exactly do those words originate?
The presidential oath of office was established in the Constitution, specifically in Article II, Section One, Clause 8. The exact text reads: “Before he enters the Execution of his Office, he shall take the following Oath or Affirmation: — 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 Constitution of the United States.”
That’s all the Constitution has to say about the swearing-in process; it does not specify who must administer the oath, although it traditionally is the Chief Justice.
A key phrase is missing from that text above, though: “So help me God.” This end part of the oath of office is actually not mentioned in the Constitution. It has commonly been said that George Washington added it during his inauguration, but some historians take issue with that, including Peter Henriques of History News Network, who says that there is no evidence that Washington used the phrase “so help me God” during his oath.
According to TIME, the first president who we know for sure said “so help me God” at his inauguration was Chester Arthur in 1881. For the next few decades, there is only concrete historical evidence of four presidents saying “so help me God,” but after 1933, the phrase was adopted by every single president, and today it’s accepted as an official part of the oath of office.
You may also notice that the Constitution gives the president the option to say “I do solemnly swear” or “I do solemnly affirm.” Every single president has used the word “swear” with the exception of Franklin Pierce in 1853, according to NPR.
The Constitution mentions nothing about requiring the president to swear on a Bible. That’s merely a tradition started by George Washington at his first inauguration, but a few presidents have broken from that over the years. In 1901, Theodore Roosevelt did not make use of a Bible, and John Quincy Adams and Franklin Pierce chose to use a law book at their inaugurations. And Lyndon Johnson, who took the oath on Air Force One following the assassination of John F. Kennedy, was sworn in on a Roman Catholic missal.
Over the years, the oath has flubbed a few times, most recently in 2009 when John Roberts read part of it incorrectly. He said “That I will execute the Office of President to the United States faithfully…” rather than “faithfully execute.” Barack Obama was clearly thrown off, and the oath was administered the second time the next day.