Final answer:
The children of the Duke and Duchess of Sussex would have a mixed racial heritage, being celebrated more in the modern era, and would likely hold dual nationality, being both British and American, thanks to laws of inherited citizenship and birthright citizenship in the U.S.
Step-by-step explanation:
Children born to the Duke and Duchess of Sussex, Prince Harry and Meghan Markle, could be considered from multiple perspectives in terms of race, ethnicity, and nationality. Prince Harry, being a member of the British royal family, comes from a predominantly white, British background.
In contrast, Meghan Markle is biracial, with a Caucasian father and an African American mother, and was born in the United States. Their children would therefore have a mixed racial heritage, which is today more commonly acknowledged and celebrated. The term Cablinasian, coined by Tiger Woods, highlights the growing acceptance of multiple racial and ethnic identities.
In terms of nationality, their offspring would likely be considered both British and American. Jus sanguinis laws mean they inherit their parents' nationalities, while the U.S. Supreme Court, via the case of United States v. Wong Kim Ark, affirms that anyone born within the United States is a U.S. citizen. Nevertheless, the societal understanding of race still evolves, influenced by history and modern legal definitions, as seen with the obsolete one-drop rule and prior miscegenation laws.