The Cambridge History of English and American Literature in 18 Volumes (1907–21).
VOLUME XVIII. Later National Literature, Part III.
§ 7. American Spelling
Dr. Johnson’s spelling has undergone some simplification in both countries: almanack, musick, errour, horrour, interiour, successour, emperour, oratour, have everywhere dropped unnecessary letters. The abandonment of the French -our for Latin -or has gone a little further in the American printing-houses; honour, humour, vigour, harbour, labour, neighbour, valour, clamour, clangour, saviour, and a few others have joined the overwhelming majority of -or words. British men of letters could be cited who have employed the same simplification. Other French spellings like theatre and centre are less common in America than in England. Parallel to the simplification of almanac(k) are wag(g)on, travel(l)er. Of the British attempts to distinguish by the spelling story, narrative (plural stories), from storey, floor (pl. storeys), and curb (bit) from kerb (stone), the first has some etymological argument in its favour, but neither has commended itself to American usage. Britons themselves are quite as likely to spell cider and pajamas in the fashion always employed in America as they are to write cyder and pyjamas.