She arranged through her mother May Lamberton Becker, literary editor of the New York Herald Tribune for single copies of 70 new significant American titles to be imported in friends' hand luggage.
It was quickly seen that books were essential good-will ambassadors, and a formal organisation was set up to run it, with branches in Britain (in London and Edinburgh) and America (in New York and Boston), first under the chairmanship of Professor Arthur Newall, and soon after by T. S. Eliot.
Another key collaborator was Alicia Street, editor of The Outpost, a newsletter published by Americans living in Britain "to promote full understanding among the English Speaking Peoples".
After the war, in February 1946, the London collection of books was presented to the South Audley Street branch of the City of Westminster Libraries at a ceremony attended by Mrs Eleanor Roosevelt.
Professor Arthur Newell, "Mrs Beatrice Warde", in The Times 25 September, 1969' p 12; Issue 57674; col G. Obituary notice, deals with her work with Books Across the Sea.