At a signal from the Principal the pupils, in ordered ranks, hands to the side, face the Flag. Another signal is given; every pupil gives the flag the military salute -- right hand lifted, palm downward, to a line with the forehead and close to it. Standing thus, all repeat together, slowly, “I pledge allegiance to my Flag and the Republic for which it stands; one Nation indivisible, with Liberty and Justice for all.” At the words, “to my Flag,” the right hand is extended gracefully, palm upward, toward the Flag, and remains in this gesture till the end of the affirmation; whereupon all hands immediately drop to the side.
(quoted from The Youth’s Companion, 65 (1892): 446–447.)
Because of its similarity to the fascist (Roman) salute, the Bellamy salute was replaced in 1942 with the modern gesture of placing the right hand over the heart.