Steve’s Barking; Is race really race? (Racism)

Modern day ( meaning 20th century and later ) seem to think in the terms  of Caucasian,  Negro, and Asian  as the only races there are. But I’ve been reading About how the English called the Irish an  inferior race. How in America we tried to keep the Poles another Slavic people out because we called them an  inferior race.
 The Japanese at one time called the Chinese an  inferior race.
Now let  look at the cast system in India would you not call that a form of racism.
The  Chinese and the Vietnamese, the Vietnamese being  inferior.
Didn’t the Arabs at one time feel that the Southern Africans were different and inferior?
Didn’t Different tribes in Africa feel that other tribes were inferior.
Even today there is talk of Jews not as being part of a religion but of a race of people.
My feeling is race is s just part of a tribal system that started at the dawn of man. Inter sexual relations within the tribes.
But what do I know,  I’m not an anthropologist.