Make them defend the opposite view.

[Tanuki]

4. Even a relatively recent textbook was called out and revised for referring

to enslaved Americans as "workers" in a pattern of "immigration."

https://www.npr.org/sections/ed/2015/10/23/450826208/why-calling-slaves-workers-is-more-than-an-editing-error

"Coby Burren was reading his textbook, sitting in geography class at Pearland High School near Houston, when he noticed a troubling caption. The 15-year-old quickly took a picture with his phone and sent it to his mother.

Next to a map of the United States describing "patterns of immigration," it read that the Atlantic slave trade brought "millions of workers from Africa to the southern United States to work on agricultural plantations."...(more)