Here is a film which is no mystery. With the ending of the Spanish-American War, there were lots of parades. New York City put up an arch for such events in Madison Square Park. Because of the speed it had to be done at, it was made of plaster. After the parade on September 30, it began to fall apart. There was some discussion of replacing it with a stone arch, but a reaction was taking place to the war in the Philippines, and that never came about. Instead it was dismantled and the statues decorating it were shipped to Charleston, South Carolina. No one quite knows what happened to them afterwards.
It's a pretty crowded image, with a narrow band of soldiers marching between crowds of onlookers. As with most crowd scenes shot by James White, there's a good view of people's backs.