A black armband symbolizes mourning a death or protesting going to war. According to North Arlington High School, black armbands were first worn in the 18th century as a sign of respect for a recent monarch's death. Black armbands are seen in sports after the death of a significant person.
Other than mourning a recent death, black armbands can also be used as a form of protest against a social or political issue. U.S. Courts reveals that wearing a black armband as a means of protest against going to war counts as freedom of speech and is protected under the First Amendment.