The difference in spelling, and the current controversy resulting from it, must be laid at the feet of the late Noah Webster, a humourless and deeply religious schoolmaster cum failed lawyer who, after 15 years’ work, published his American Dictionary of the English Language in 1828. One cannot imagine an individual less well suited to the creation of a dictionary; he knew very little of other languages, his ideas about etymology were based more on religion and wishful thinking than historical fact (he thought all languages derived from ancient Chaldee), and he had this bee in his bonnet about simplifying the language by removing unnecessary letters from words.
His most influential book was not the Dictionary, but the earlier American Spelling Book, which went through about three hundred editions during his lifetime and after. This was very conventional by the standards of his day. It was only later that he began to advocate spelling reform, especially in a piece that had the splendid title An Essay on the Necessity, Advantages and Practicability of Reforming the Mode of Spelling, and of Rendering the Orthography of Words Correspondent to the Pronunciation, published in 1789.
His aim was to remove all extraneous letters from words and he put forward a whole range of suggestions to this end. His aim was also political: he wanted to make American orthography distinctive and through this to help weld the disparate 13 founding colonies into a nation. By 1806, though, when he published his first dictionary, he had backtracked on the more outlandish of his ideas, saying “it would be useless to attempt any change, even if practicable, in those anomalies which form whole classes of words, and in which, change would rather perplex than ease the learner” (still a strong argument against spelling reform).
Because of his spelling revisions in the 1828 dictionary, Americans now write color, jewelry, theater and aluminum, as well as sulfur. Had it not been for the conservatism of his readers and publisher—and a “dictionary war” with a rival—that forced him to modify his views, Americans would also now have tuf (for tough), groop (for group) and tung (for tongue) among many others.