The Pledge of Allegiance
The Pledge of Allegiance was first published for Columbus Day, on September 8, 1892, in the Boston magazine The Youth's Companion. It was written by a member of the magazine's staff, Francis Bellamy. The publication of the Pledge, and its wide redistribution to schools in pamphlet form later that year lead to a recitation by millions of school children, starting a tradition that continues today.
The original text is: "I pledge of allegiance to my flag and the Republic for which it stands - One nation indivisible - with liberty and justice for all."
Several minor changes to the text, including changing "my flag" to "to the Flag of the United States of America," were made over time, some "official" and some less so.
In its 1940 Gobitis decision (310 US 586), the Supreme Court ruled that schools can compel students to recite the Pledge. The U.S. Congress recognized the Pledge officially in 1942, and in 1954 added the phrase "under God" to the text. In 1943, the Supreme Court overturned Gobitis and ruled in its Barnette decision (319 US 624) that school children could not be forced to recite the Pledge as a part of their school day routine.
Today, the wording of the Pledge of Allegiance is set in the US Code, at 4 USC 4. The text of that section is below.
If you would like more information on the U.S. flag, I suggest that you visit USFlag.org, an excellent site with lots of resources concerning the flag and its evolution.
The Pledge of Allegiance to the Flag, "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.", should be rendered by standing at attention facing the flag with the right hand over the heart. When not in uniform men should remove their headdress with their right hand and hold it at the left shoulder, the hand being over the heart. Persons in uniform should remain silent, face the flag, and render the military salute.