Grammar and Good Taste. Reforming the American Language. By DENNIS E. BARON. New Haven: Yale University Press, 1982.I don't have a copy of the book, but he's done a couple of recent posts on his blog Web of Language (here). As usual, Baron has a good take on things, focusing on how English spelling is insane but the chances of reform virtually nil.
He also notes that spelling really doesn't matter much. This is true, but it sure hasn't stopped language communities that could devote energies to better pursuits from obsessing over it: With almost every endangered language I know anything about, language specialists have spent a lot of time and effort on spelling, often without particularly good results for it.
But I had forgotten a famous chapter in American spelling: There was an effort that in 1906 got support from a president order, aiming to reform about 300 words, including though > tho and through > thru. These ultimately failed, of course, but you certainly do see them in old documents from that era.