The Pledge of Allegiance is a short speech that goes: "I pledge allegiance to the flag of the United States of America, and to the Republic for which it stands, one Nation under God, indivisible, with liberty and justice for all." In the United States, it is often recited at public events and it is commonly recited at public schools, especially elementary schools. To recite the Pledge of Allegiance, school children are meant to stand facing the American flag with their right hand on their heart.

The Pledge of Allegiance was written in 1892 by a Baptist minister and socialist author named Francis Bellamy. Bellamy wrote the pledge of allegiance as part of an advertising campaign for a magazine called Youth's Companion, as a way to celebrate the 400-year anniversary of Christopher Columbus' journey to America. Bellamy's original Pledge of Allegiance, however, did not include any reference to God.

The inclusion of the phrase "under God" to the Pledge of Allegiance was inspired by a Catholic group called the Knights of Columbus, who added the phrase to their own recitals in 1951, and attempted to make it a formal part of the pledge. However, the Pledge of Allegiance was not officially changed to include the phrase until 1954, when Minister George Docherty recited a sermon about the Pledge, while president Eisenhower was in attendance. Docherty and Eisenhower spoke after the sermon, and Eisenhower introduced legislation to modify the Pledge of Allegiance the next day. Since that time, "under God" has been officially recognized as a part of the Pledge of Allegiance.

However, many people dispute the allowance of the phrase "under God" in the Pledge of Allegiance. They argue that, because the pledge is recited in public schools and at public events, it breaks the First Amendment claim of separation of church and state. In 2002, a case was brought to the Supreme Court by Michael Newdow, an atheist who did not want his daughter to have to recite the words "under God" in her classroom. However, the Supreme Court ultimately claimed that Newdow did not have the right to bring the case to trial, because he was divorced and was not the parent with primary custody. Because of this, they did not have to make a judgment regarding whether the Pledge of Allegiance represented a breach of the First Amendment.