June Swanson 
I Pledge Allegiance, 2nd Edition [PDF ebook] 

In this inspiring and relevant book, discover how "The Pledge of Allegiance" has become one of the enduring symbols of America’s pride. In 1888, a children’s magazine announced that a new holiday–Columbus Day–would begin in 1892, on which the American flag would be raised to celebrate the founding of America. As the flag was raised, children would say something to honor it. What resulted was a simple one-line poem that became known as "The Pledge of Allegiance." after more than a hundred years, the poem has changed very little, and is still recited in classrooms across America.