Massachusetts’ Supreme Judicial Court – the state’s highest court – will hear arguments today in Doe v. Acton-Boxborough Regional School District, a case in which an anonymous atheist couple is challenging the use of the phrase “under God” in recitations of the Pledge of Allegiance in public schools. The plaintiffs, represented by the American Humanist Association, are appealing a lower court ruling that went in favor of the school district.

With the school year getting underway around the country, here are five facts about the Pledge of Allegiance and its legal history:

The original version of the Pledge of Allegiance did not include the words “under God.” The patriotic oath – attributed to a Baptist minister named Francis Bellamy and published in a children’s magazine in September 1892 to commemorate the 400th anniversary of Christopher Columbus’ voyage to America – read: “I pledge allegiance to my flag and to the Republic for which it stands, one nation, indivisible, with liberty and justice for all.”

Congress added “Under God” to the Pledge in 1954 – during the Cold War. Many members of Congress reportedly wanted to emphasize the distinctions between the United States and the officially atheistic Soviet Union.

The children of the plaintiffs in the Massachusetts case – like all Americans – cannot be required to recite the Pledge or any specific part of it. That was made clear in a 1943 U.S. Supreme Court decision, West Virginia v. Barnette, in which Justice Robert Jackson wrote: “If there is any fixed star in our constitutional constellation, it is that no official, high or petty, can prescribe what shall be orthodox in politics, nationalism, religion, or other matters of opinion or force citizens to confess by word or act their faith therein. If there are any circumstances which permit an exception, they do not now occur to us.”

In 2004, the U.S. Supreme Court accepted a case (Elk Grove Unified School District v. Newdow) that challenged the use of “under God” in the Pledge, but the high court did not rule on the question of whether the Pledge is constitutional under the First Amendment. Instead, a five-justice majority said that atheist Michael Newdow did not have legal standing to bring the case on behalf of his daughter because he did not have legal custody of her. Standing is a legal concept that only those with a legitimate stake in a case’s outcome can be a party to a lawsuit.

The current Massachusetts case challenges the Pledge from a different perspective than did Michael Newdow, who argued that “under God” in the Pledge violates the prohibition on the establishment of religion in the First Amendment of the U.S. Constitution. According to the Religion News Service, the plaintiffs in this new case are arguing that the recitation of the pledge discriminates against non-believing students and thus violates the guarantee of equal rights contained in the Massachusetts Constitution.