Answer: in 1892 to mark the 400th anniversary of Columbus’s arrival in America. The original pledge attributed to Edward Bellamy, a minister, read:
I pledge allegiance to my Flag and the Republic for which it stands, one nation, indivisible, with liberty and justice for all.
Source: US Histoy.org
It did not include the words “under God,” added in 1953 as a reaction against the Cold War threat of “godless communism.”
San Francisco, Calif., April 1942 – Children of the Weill public school, from the so-called international settlement, shown in a flag pledge ceremony. Some of them are evacuees of Japanese ancestry who will be housed in War relocation authority centers for the duration (Library of Congress)
This photograph is attributed to Dorothea Lange, the famed photographer, who died on October 11, 1965.
For more on Columbus Day, see my previous post “The World is a Pear.”