In this 1964 file photo, an unidentified black civil rights demonstrator carries a U.S. flag outside the Alhambra Theatre in Harlem neighborhood of New York. “Flags are, by their nature, emotion-charged emblems, and that's especially the case in the U.S.”, says John Hartvigsen, president of the North American Vexillological Association, a group of scholars dedicated to the study of flags. (Photo by AP Photo)
