Time to review your history and geography.
Jamaica is in the Americas
Black Africans, were enslaved in Jamaica
Their descendants, even if mixed with indigenous peoples (Caribbean Indian) or Whites are considered Black (in most cases).
If they immigrated to the US, they are Classified African-American
The current 2020 Census, being conducted by the Trump Administration, asks respondents for Race. If the answer is Black, it acts for origins. Jamaica is one of the choices.
Blacks in the Americas since before 1808 came as slaves. Their descendants are African-American if they end up in the USA (unless they CHOOSE to be known as Mixed Race).