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.
The Pledge of Allegiance is just 31 words long. Its history, on the other hand, is quite lengthy.
Francis Bellamy, a Christian minister, penned the patriotic sentence in 1892 to mark the 400th anniversary of Christopher Columbus's arrival in the Americas. He wrote at the time for a general-interest magazine called the Youth's Companion, which published the pledge to encourage schoolchildren to recite it each morning.
Schools would need to purchase flags for students to do so, according to pledge expert Shelley Lapkoff, and the magazine just happened to sell them.
"It was both to get people to have flags, in keeping with their belief of patriotism, and then also to help their business," Lapkoff said. "I believe the reason that flags are so predominant in our culture is because of the Pledge of Allegiance and this mass-marketing campaign that went on."
It's still a public-school tradition to say the pledge each morning, though the accompanying gesture has switched from an outstretched hand to a hand-over-heart salute, according to Elizabeth Brown, a reference librarian at the Library of Congress.
"It's just so much a part of the fabric of American society," Brown said. "We all grew up with it in our schools and our scout meetings and at so many events."
The pledge itself is more of a patchwork quilt.
The words "my flag" initially appeared instead of "flag of the United States," Lapkoff said. Bellamy wanted any country to be able to say the same pledge. But several political organizations at the 1923 National Flag Conference agreed to change the wording in an effort to boost American patriotism, Lapkoff said, and it has been that way since.
"Under God," the pledge's most controversial phrase, was added 31 years later. Tensions at the time were high between the United States and the Soviet Union, a group of nations that embraced communism. Belief in God was something communists did not support.
In 1952, a Catholic group called the Knights of Columbus urged Congress to add "under God" to the pledge. The effort stalled. But the Reverend George Docherty, a Presbyterian minister, revived the idea when he preached about it at his D.C. church on February 7, 1954. The special guest that day was President Dwight D. Eisenhower. Support grew quickly, and Congress passed a resolution that spring to add the words. Eisenhower signed it into a law on June 14, Flag Day.
Brown, the librarian, said it's surprising that the original pledge didn't include the words.
"Bellamy was a minister, which makes you wonder why 'under God' didn't get in there sooner," she said.
That part of the pledge has upset some people. The Constitution's First Amendment says Congress can't establish an official religion or favor one religion over another. A few people have argued in court that reciting a pledge that mentions one God goes against the First Amendment. But the courts have mostly rejected that idea, because saying the pledge and saluting the flag is voluntary. (The Supreme Court ruled on that issue in 1943.)
Lapkoff said she's grateful that the pledge has helped people keep thinking about what it means to be American.
"I think people have different ideas about patriotism now," she said. "The Pledge of Allegiance has been instrumental to defining freedom of speech."
Clarification: An earlier version of this story stated that the First Amendment established the separation of church and state. The First Amendment says that Congress can't establish a religion or make laws that favor one religion over another. Thomas Jefferson later wrote that the result of the amendment was "a wall of separation between Church & State." This story has been updated.