In the following sentence, is it correct the use of the verb was?
As both Engines of Privilege and another new book on the top tier of private schools, Gilded Youth by James Brooke-Smith, explain, the origins of England’s famous boys’ “public schools” was as charitable foundations set up to educate the poor of their locality.
If so, why?
The sentence appears in the article 'What to do about Britain’s private school problem?' in the Financial Times.