(CNN) -- Here's a look at what you need to know about The Pledge of Allegiance, a promise of loyalty to the United States.
Facts: "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"
During the Pledge, proper etiquette requires military personnel in uniform to salute, while other citizens place their right hand on their heart. Men should remove their hats during the pledge.
There was confusion about who wrote the pledge, James B. Upham or Francis Bellamy, both editors at "The Youth's Companion," but Bellamy is now acknowledged as the author.
History: September 18, 1892 - The pledge is published for the first time in the juvenile magazine "The Youth's Companion." The pledge is written to celebrate the 400th anniversary of the discovery of America.
1924 - The words "the flag of the United States of America" put in place of "my Flag." The pledge was originally written - "I pledge allegiance to my Flag and the Republic for which it stands, one nation indivisible, with liberty and justice for all."
1942 - The pledge is recognized by the U.S. government.
1943 - In West Virginia State Board of Education vs. Barnette (319 U.S. 624), the Supreme Court rules that requiring a person to say the pledge is violating the first and fourteenth amendments. The case involved a Jehovah's Witness student refusing to say the pledge in schools on the grounds it was against his or her religious beliefs.
1954 - President Dwight D. Eisenhower asks Congress to add "under God" to the pledge. Congress adds the phrase.
1998 - Dr. Michael Newdow files suit against the school board of Broward County (Florida) to get the phrase "under God" removed from the pledge. The suit is dismissed for lack of standing. Sandy Banning, the mother of the girl, says that her daughter is not an atheist and has not been harmed by saying the pledge in school. Banning and Newdow have faced custody issues over their daughter.
2000 - Newdow, who is an atheist, brings the case against the Elk Grove school system in California. His daughter attends Florence Markofer Elementary School in Elk Grove.
June 26, 2002 - The 9th Circuit Court of Appeals decides that reciting the Pledge of Allegiance in public schools is an unconstitutional "endorsement of religion" because of the phrase "under God."
March 24, 2004 - Newdow argues his case before the Supreme Court.
June 14, 2004 - The U.S. Supreme Court dismisses the challenge to the constitutionality of the Pledge of Allegiance on a technicality, saying Newdow does not have legal standing to bring the case.
January 3, 2005 - Michael Newdow and eight co-plaintiffs file suit in a Sacramento federal court, seeking to remove the phrase "under God" from the Pledge of Allegiance. The eight co-plaintiffs are not named but are parents with custody of their children or children themselves.
July 18, 2005 - Michael Newdow reopens his case and sues four Sacramento area school districts on behalf of his family and several others.
August 10, 2005 - The 4th U.S. Circuit Court of Appeals upholds a Virginia law that requires public schools to recite the Pledge of Allegiance daily, and rejects a claim that its reference to God is an unconstitutional promotion of religion. The court states that the pledge is not an affirmation of religion similar to a prayer, but simply a patriotic exercise. This suit is raised by a father of three, Edward Myers of Sterling, Virgina, who doesn't believe his children should have to say "one nation under God."
September 14, 2005 - Reciting the Pledge of Allegiance in schools is ruled unconstitutional by U.S. District Judge Lawrence Karlton of U.S. District Court in the Eastern District of California, in Sacramento. He states that the phrase "under God" violates the children's right to be "free from a coercive requirement to affirm God."
January 2009 - Frazier vs. Alexandre - The U.S. 11th Circuit Court of Appeals issues a ruling stating under parents written request, schools can excuse a student from reciting the pledge regardless of the student's personal beliefs.
March 11, 2010 - Newdon vs. Rio Linda Union School District - Michael Newdon, Sacramento attorney, loses his case to remove the words "under God" from the pledge. Newdon has publically fought to remove "God" from the pledge and U.S. currency. Judge Carlos T. Bea writes, "The pledge is one of allegiance to our republic, not of allegiance to the God or to any religion."
November 12, 2010 - The First U.S. Circuit Court of Appeals upholds a lower court ruling that a New Hampshire law requiring schools to recite the Pledge is not unconstitutional.
October 5, 2012 - State of Michigan Governor Rick Snyder signs legislation that will give all Michigan students the freedom of reciting the Pledge of Allegiance in class.