US children saluting the flag in 1941.
Known as the “Bellamy salute“, it was devised by the author of our Pledge of Allegiance, Francis Bellamy and first demonstrated in 1892 for Columbus Day, of all days.
Continuing down the historical rabbit hole, have a read from Columbus’ log about his first encounter with the indigenous tribes in the “New” world:
They … brought us parrots and balls of cotton and spears and many other things, which they exchanged for the glass beads and hawks’ bells. They willingly traded everything they owned… They were well-built, with good bodies and handsome features…. They do not bear arms, and do not know them, for I showed them a sword, they took it by the edge and cut themselves out of ignorance. They have no iron. Their spears are made of cane… . They would make fine servants…. With fifty men we could subjugate them all and make them do whatever we want.
Summary from Howard Zinn’s “A People’s History of the United States”, pg.1. See Columbus’ full journal entry (begin at October 11) here.