I did not say there were many races...I said "breeds".
Just as there is only one dog, but many breeds.
Mankind is mankind...but physical characteristics carry over, and can be bred within humans ( to an extent ), just as within animals.
Blue eyes, light skin, blond hair, etc.
Take a look at Hitler and his genetic programs to purify the "Arian" race sometime.
Speaking of all-white people, you remind me of the Elizabeth Warren case. Sure, God made us each unique in both personality and physical characteristics. Here is a short AiG video that confirms what you are saying:
The Origin of Races