How\when/who did racism start?

It's a variation on tribalism. In our hunter-gatherer days, we staked out our bit of the jungle - as large as we could defend - and only allowed our extended family to hunt and gather there. Someone with a different colour of skin is obviously not from your extended family, so you attack them. I always find it ironic when white supremacists claim that black people should live in the jungle.

People started it, long before recorded history. People have always been wary of "the other lot".

The word "racism" is probably recent, possibly less than 100 years old, almost certainly less then 200 years old.

In prehistoric times when you hated your neighbor because he might poach on your hunting grounds and leave your family starving. It was a survival instinct.

That's an unanswerable question. Man has always been biased against others who are different from themselves - it's in our nature, so it's been with us for THOUSANDS of years.

Noah and Ham

ach, du liebe

Idk

6000 BC

Ever since Cain slew Abel pretty much

You think some guy invented it??
Ghost gave a very good answer. People also tend to fear something that's different.

may 4 in the year 5479 BC

This is start ancient period almost people like and start racism America and Africa most harmful start that.

The concept of race is tied to Queen Isabella and King Ferdinand of Spain. They introduced the concept that the Spanish people were a separate race than Jewish or Muslim persons. Prior to then , there was no such concept.