Unlike the European patronymic tradition, the history of Asian surnames is profoundly ancient, often tied to royal dynasties, ancestral clans, or geographic locations dating back millennia. For instance, in countries like China and Korea, a relatively small pool of surnames covers a vast majority of the population—a statistical concentration that naturally transferred to the American diaspora.
The high prevalence of Vietnamese names like Nguyen is rooted in historical dynastic shifts, where citizens would adopt the surname of the newly ruling family as a display of loyalty. Following the wave of immigration post-1975, Nguyen quickly became one of the most common family names in the United States.
Furthermore, the varied spellings of these names in America are largely the result of "Romanization"—the process of converting non-Latin scripts (like Hanzi, Hangul, or Devanagari) into the English alphabet. Because early immigration officials relied on phonetics, a single ancestral name could be recorded in multiple ways; for example, the Chinese surname Zheng might be written as Chang or Cheng depending on the immigrant's regional dialect.