Pledge of Allegiance, in full, Pledge of Allegiance to the Flag of the United States of America, oath that proclaims loyalty to the United States. and its national symbol. It reads: "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." According to the U.S. flag code, it should be recited while standing at attention with the right hand over the heart; military personnel must salute. The pledge first appeared, in a slightly different form, in a mass-circulation magazine for young people, The Youth's Companion, in the Sept. 8, 1892, issue. Authorship has been ascribed to Francis Bellamy (1855-1931), cousin of Edward Bellamy and a socialist, former Baptist minister, and magazine staff member. A month later the pledge was first used publicly in school ceremonies celebrating Columbus Day.

In 1924 the oath's wording was changed slightly (the original "my flag" became "the flag of the United States of America"). Officially recognized by the government in 1942, the pledge became compulsory in some public schools, but the following year the Supreme Court ruled (in West Virginia State Board of Education v. Barnette) that recitation could not be required of any individual. It continues, however, to be mandatory or recommended in a majority of the states and is a daily fixture in most American classrooms. The final alteration to the pledge occurred in 1954 when, by a joint order of Congress, the words "under God" were inserted. The change is usually ascribed to a cold-war attempt at differentiating the United States from officially atheistic Communist countries. The addition caused little stir when it was enacted, but in 2002 opposition to it resulted in a federal appeals court ruling that the words are unconstitutional because they violate the First Amendment's prohibition against government endorsement of religion. The Supreme Court subsequently overturned the verdict on procedural grounds.