How big of a theme is this theory in 1619? From reading your first first link earlier in the thread it sounded like the book had lots of other things discussed and this theory about the revolution cause was just a teeny tiny part?
And it most certainly should be brought up as a theory.... It is NOT to make you or children feel bad... This book is not a school text book for k-12, and never has been.
Since Britain abolished slavery in England in 1772, it was a POSSIBLE reason for the South to worry they would do the same in America. Anyone could come to that possibility.....of being an underlying cause for the South to join the Patriots who wanted their tea......tax free!

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It turned out the British did not abolish slavery in the Caribbean for another 60 years.... So the argument against such a possibility that the southern states were concerned on what would happen to them and their slaves can be argued against, but only in HINDSIGHT..... now we know the Brits did not ban slavery in their islands in the Caribbean for another 60 years after they abolished it at home. But would the slave owners in America know that, at the time....know how to see the future? I think not.
It's worthy of discussion and in depth study on it.
It's worth the argument....
Banning a book because you disagree on a point made in it, is still wrong, wrong, wrong imo.
Our minds need exercise and stretching beyond George Washington admitting to his father, he cut down the cherry tree.... don't ya think? College is for exercising the mind imo.