Vin Diesel was born in the U.S. and is an American citizen.
Dwayne Johnson also known as The Rock was also born in the U.S. and is American. Dwayne Johnson's ethnic background is Samoan and African Canadian according to what I found on the net and Vin Diesel's is African American and Italian.
The Rock is Samoan and African American I beleive and I'm not really sure what Vin Diesel is...
Some websites say he's Half African American and Italian but that does'nt sound right..... Hope this helps :)