Well, it's not really clear-cut, which is part of my point, but probably the 2 most significant people I could think of would be Babbage and Turing, both of whom were English. Definitely could make arguments about what is or isn't considered a 'computer', to the point where it's fuzzy, but regardless of how you look at it, 'computers were invented in America' is rather a stretch.
Who wants to tell the author that not everything was invented in the US? (And computers certainly weren't)