* Historical Influence: The pronunciation of "herb" has changed over time. In Middle English, it was pronounced with the "h" sound. However, in British English, the "h" sound started to disappear over centuries. American English, however, retained the older pronunciation.
* Prestige & Authority: In the 18th and 19th centuries, American English was heavily influenced by British English. However, Americans also wanted to establish their own identity, leading them to hold onto some of the older pronunciations that differed from British English. This included the "h" in "herb."
* Regional Variations: While the "h" sound in "herb" is prevalent in American English, there are still regional variations. In some parts of the United States, particularly in the South, people may pronounce it without the "h" sound.
Ultimately, the pronunciation of "herb" with the "h" sound in American English is a combination of historical influences, linguistic evolution, and a desire to establish a distinct American identity.