During the late 19th century, because of misbehavior related to the Opium Wars, all males of Chinese descent over age 18 in America were forced to wear their hair in an identifying queue. A queue is a single long braid. It had long been worn by poppy farmers in China, and became a fashion among the Manchu by 1900, but in San Francisco and other cities the U.S. government made the queue mandatory as a way of punishing, identifying and humiliating Chinese male immigrants, who were accused of defiling local white women (largely false) and running opium dens and trafficking the drug to Americans (largely true). The queue was already a Chinese male fashion, roughly like a beard to us, but imagine a foreign government making it mandatory. For a while this happened and is why Chinese men are shown wearing it in the art and photographs of the period.

https://scalar.usc.edu/works/stereotyping-in-american-through-the-centuries/chinese-immigrants-in-19th-century-america--conclusion

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My grandfather was Chinese. His father and grandfather, he said, were forced to wear queue. They hated it.