The Pledge of Allegiance of the United States is a patriotic recited verse that promises allegiance to the flag of the United States and the republic of the United States of America. The first version, with a text different from the one used at present, was written in 1885 by Captain George Thatcher Balch, a Union Army officer in the Civil War who later authored a book on how to teach patriotism to children in public schools. In 1892, Francis Bellamy revised Balch's verse as part of a magazine promotion surrounding the World's Columbian Exposition, which celebrated the 400th anniversary of Christopher Columbus' arrival in the Americas. Bellamy, the circulation manager for The Youth's Companion magazine, helped persuade then-president Benjamin Harrison to institute Columbus Day as a national holiday and lobbied Congress for a national school celebration of the day. The magazine sent leaflets containing part of Bellamy's Pledge of Allegiance to schools across the country and on October 21, 1892, over 10,000 children recited the verse together.