In the Federal Government, in order for an official to take office, he or she must first take the oath of office; this is also known as a swearing-in ceremony. The official reciting the oath swears an allegiance to uphold the Constitution. The Constitution only specifies an oath of office for the President; however, Article VI of the Constitution states that other officials, including members of Congress, "shall be bound by Oath or Affirmation to support this constitution."

The following includes oath information for high ranking officials from each of the three branches of Government.

Executive Branch: President and Vice President of the United States

According to the 20th Amendment to the Constitution, a President's term of office begins at 12:00 p.m. (noon) on January 20th of the year following an election. To assume his or her duties, the President-elect must take the Oath of Office as stated in Article II, Section I , Clause 8 of the Constitution:

Before he enter on 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.”

The Constitution does not say what the swearing-in must include. While most Presidents-elect chose a Bible, as George Washington did, John Quincy Adams used a book of law, and Teddy Roosevelt did not use any book.

The President-elect is usually sworn in by the Chief Justice of the U.S. Supreme Court, but not always. Lyndon Johnson was sworn in by Sarah T. Hughes, a U.S. District Judge in Texas, after the death of John F. Kennedy. Calvin Coolidge was sworn in by his father, a notary public and justice of the peace, after the death of Warren G. Harding.

The Vice President also takes an oath of office. Until 1933, the Vice President took the oath of office in the Senate; today, both the President and Vice President are inaugurated in the same ceremony. The Vice President's oath is administered immediately before the President's. The Vice President's oath may be administered by the retiring Vice President, by a member of Congress, or by some other Government official, such as a justice of the Supreme Court. The Vice President's oath is as follows:

"I do solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic, that I will bear true faith and allegiance to the same: that I take this obligation freely, without any mental reservation or purpose of evasion, and I will well and faithfully discharge the duties of the office on which I am about to enter. So help me God."

Legislative Branch: Members of Congress

At the start of each new Congress, in January of every odd-numbered year, the entire House of Representatives and one-third of the Senate takes an oath of office. For Members of the House, the Speaker will direct the Members to rise, and the oath is administered. A Senator-elect takes the oath of office from the presiding officer in an open session of the Senate. The current oath is as follows:

"I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God."

Judicial Branch: Supreme Court Justices

According to Title 28, Chapter I, Part 453 of the United States Code, each Supreme Court Justice takes the following oath:

"I, [NAME], do solemnly swear (or affirm) that I will administer justice without respect to persons, and do equal right to the poor and to the rich, and that I will faithfully and impartially discharge and perform all the duties incumbent upon me as [TITLE] under the Constitution and laws of the United States. So help me God.''

Oath of Office facts and figures:

• The original oath for members of Congress included the words, "I do solemnly swear (or affirm) that I will support the Constitution of the United States." The oath was revised during the Civil War, when members of Congress were concerned about traitors.
• In 2009, when Chief Justice John Roberts swore in President Barack Obama at his first inauguration, the Chief Justice made a small mistake in reciting the oath; the next day, the oath was privately administered without incident.

To learn more, see the Oath of Office from the U.S. Senate site and the Presidential Oaths of Office from the Library of Congress site.