[5] The phrase "So help me God" is prescribed in oaths as early as the Judiciary Act of 1789, for U.S. officers other than the President.
[8] There is no law that requires Presidents to add the words "So help me God" at the end of the oath (or to use a Bible).
Some historians maintain that George Washington himself added the phrase to the end of his first oath, setting a precedent for future presidents and continuing what was already established practice in his day[9] and that all Presidents since have used this phrase, according to Marvin Pinkert, executive director of the National Archives Experience.
[11] These historians further note that "we have no convincing contemporary evidence that any president said "so help me God" until September 1881, when Chester A. Arthur took the oath after the death of James Garfield.
Richard Gardiner's research published in the White House History Quarterly, November 2024, offers contemporary evidence for presidents who used the phrase going back to William Henry Harrison in 1841, and Andrew Jackson.
[15] The Air Force announced on September 17, 2014, that it revoked this previous policy change, allowing anyone to omit "so help me God" from the oath.
Alabama, Connecticut, Delaware, Kentucky, Louisiana, Maine, Mississippi, New Mexico, North Carolina, Texas, and Virginia retain the required "so help me God" as part of the oath to public office.
Saying the phrase while taking the presidential oath does not force a certain belief on the President and does not infringe on their religious freedoms.
In medieval France, tradition held that when the Duke of Brittany or other royalty entered the city of Rennes, they would proclaim Et qu'ainsi Dieu me soit en aide ("And so help me God").
In such proceedings, the judge first speaks the words You swear [by God Almighty and All-Knowing] that to the best of your knowledge you have spoken the pure truth and not concealed anything.
The traditional oath of witnesses in Austrian courts ends with the phrase so wahr mir Gott helfe.
The phrase so wahr mir Gott helfe is also an (optional) part in the oath of surveyors who testify as expert witnesses as well as court-certified interpreters.