How Old It Actually Is:
The idea of pledging allegiance to the flag was basically an early viral marketing gimmick. It was first published in 1892 in a wildly popular children's magazine named The Youth's Companion. The much-bitched-about "under God" was only added to the pledge in 1954.
Who Made It Up:
Daniel Ford, the man who ran The Youth's Companion, dreamed of putting an American flag in every classroom in the country.
The man loved him some America.
Within a year, 30,000 flags had been sold. Our calculators tell us that comes out to $300,000, which was a lot more impressive a sum in 1892. The man who actually wrote the pledge was a former minister named Francis Bellamy. He was a Socialist (aka, a dirty commie) whose stated mission was to create in America's youth a habit of automatic reverence and utter loyalty to the country. He even came up with an original salute for children to give while reciting the pledge...
Things got awkward around '41.