It is around 337 years old. Prior to 1681, “White” was not the common designation used to describe people. They were English, French, Portuguese, etc. Whiteness is a designation used to create a caste system after Bacon's Rebellion in order to divide the poor so they wouldn't rise against the wealthy elite ever again.

When Whites were created somewhere around 1681, Blacks who'd previously been of the same class as all other indentured servants suddenly switched from being indentured servants to being enslaved. Newly minted “White” people who'd been dirt poor and reviled were now given status in this new caste system with all of the rights and privileges that were stripped from Black people.

For further detail, please see my earlier answer:

Laura Sands's answer to When did the racism between white and black people start?