On June 14, 1954, President Dwight Eisenhower signed a bill to insert the phrase “under God” into the U.S. Pledge of Allegiance that children recited every morning in school. Previously, the pledge—originally written in 1892—had contained no reference to religion.

The push to add “under God” to the pledge gained momentum during the second Red Scare, a period when U.S. politicians were keen to assert the moral superiority of U.S. capitalism over Soviet communism, which many conservatives regarded as “godless.”

Court cases about whether students should recite the pledge had already reached the U.S. Supreme Court in the 1940s, before “under God” was added. In the decades after the 1954 addition, there were numerous other lawsuits related to the pledge.

Video: Freedom of Religion in the United States

The first version of the Pledge of Allegiance was written for the Columbian Exposition in October 1892 to mark the 400th anniversary of Christopher Columbus’ arrival in the Americas. Historians have long identified its author as Francis Bellamy, an ordained Baptist minister and Christian socialist who got a job working for the family magazine Youth's Companion. (In 2022, historians raised new questions about whether Bellamy wrote the pledge himself or stole it from a boy who submitted it to the magazine.)

As a marketing gimmick, Bellamy put together a program for schools to use to mark the Columbian Exposition, and successfully lobbied Congress to support the program. Part of this program was a Pledge of Allegiance, which originally read:

“I pledge allegiance to my flag and the Republic for which it stands—one Nation indivisible—with liberty and justice for all.”

Like the magazine’s other marketing strategies, which included sending flags and pictures of George Washington to schools, the pledge was part of a push for “Americanization.” Bellamy was one of many Protestant Americans of northern European heritage who believed that new immigrants from southern and eastern Europe, many of them Catholic, were harmful to the “American” way of life, and that they needed to assimilate.

Over the next few decades, schools and organizations that chose to recite a pledge used variations of Youth’s Companion’s version or made up their own pledges. One June 22, 1942—just over six months after the United States entered World War II—the U.S. government officially recognized a standard version of the pledge for the first time when Franklin D. Roosevelt signed the U.S. Flag Code.

The pledge in the Flag Code was a version of Youth’s Companion’s original pledge, and still contained no reference to God. Even so, the issue of whether children should recite the pledge in school came up in two Supreme Court cases around this time.

In 1940, the court ruled in Minersville School District v. Gobitis that forcing Jehovah’s Witnesses to recite the pledge in school was not a violation of their religious freedom (Jehovah’s Witnesses consider saluting a flag an act of worship). Three years later, the court reversed this decision in West Virginia State Board of Education v. Barnette in another case involving Jehovah’s Witnesses, ruling that forcing students to recite the pledge was a violation of their First Amendment rights.

One of the first major groups to call for the addition of “under God” to the pledge was the Knights of Columbus, a Catholic fraternal organization. In 1952, it began petitioning the federal government to add the phrase to the Pledge of Allegiance. U.S. Representative Louis C. Rabaut, a Democrat from Michigan, was persuaded by the petition, and introduced legislation to add the phrase to the pledge.

Rabaut argued that adding the phrase would give students “a deeper understanding of the real meaning of patriotism,” while adding that it could also provide “a bulwark against communism.” In February 1954, Eisenhower attended a sermon by Reverend George Docherty at the New York Avenue Presbyterian Church in Washington, D.C. that greatly influenced his ideas on the subject.

“To omit the words ‘under God’ in the Pledge of Allegiance is to omit the definitive factor in the American way of life,” Docherty preached. He discounted the right of atheists to object, arguing that an “atheistic American is a contradiction in terms,” because if “you deny the Christian ethic, you fall short of the American ideal of life.”

With Eisenhower on board, the campaign to adopt the phrase had more momentum. On June 14, Flag Day, Eisenhower signed a law adding “under God” to the Pledge of Allegiance. Two years later, Eisenhower also made “In God We Trust” the United States’ official motto (it did not appear on paper currency or stamps before the 1950s).

The addition of “under God” to the pledge led to new lawsuits about whether it violated the rights of students and teachers. In the 1950s and ‘60s, the prominent atheist Joseph L. Lewis filed lawsuits against the state of New York over the pledge. Over the next several decades, similar cases were filed in different states, with the most prominent cases reaching federal courts and even the U.S. Supreme Court in the 21st century.

In 2004, the Supreme Court sided against Michael Newdow, who objected to his daughter having to say the pledge in Elk Grove Unified School District v. Newdow, on the grounds that he didn’t have sufficient custody over his daughter to make the complaint. In 2010, the U.S. 9th Circuit Court of Appeals ruled against Newdow in a separate but related lawsuit, arguing that the pledge didn’t violate students’ rights because they can choose not to participate.