I found the following interesting and quite 'revealing.'
From Napoleon and the British by Stuart Semmel, xiii, A Note on Spelling and Punctuation:
'Unless otherwise indicated, italics in quotations are original to the sources. Spelling mistakes and typographical errors in quotations have generally been preserved and indicated. Certain spellings that depart from twenty-first century British practice, and which might appear to be the work of an American transcriber-for example, 'honor' and 'center'- were in fact the spellings employed by late Hanoverians, before a desire to Frenchify British spelling exerted itself later in the nineteenth century. In this sense…modern American usage remains closer than modern British usage to 'the king's English'-if the king in question is George III.'
Now isn't that both revealing and a surprise. So, modern British spelling is apparently French-inspired. 😀