The first two books published by Charles L. Webster and Co. in the United States were The Adventures of Huckleberry Finn, by Mark Twain (Samuel Clemens), and Grant's Memoirs. Both came out in 1885.
Webster was the husband of the niece of Clemens, who had essentially set up the firm himself because he thought he was getting a raw deal from other publishers. He thought the same about the proposed deal his friend Grant was considering from the Century publishing company, and persuaded the general to go with the Webster firm instead.
Huckleberry Finn was the greatest American novel written up to that time -- and perhaps up to this time. Grant's book remains the best presidential memoir (albeit not about his presidency). Both works made considerable money for their authors (or in Grant's case the author's widow), and the publisher.
Clemens' focus on lecturing and business, especially publishing Grant's book, left him less time for writing in 1885, although he did come up with the superb short story or autobiographical fragment, The Private History of a Campaign That Failed. That story was among the last works which drew upon the creative wellspring of his Missouri childhood and youth. In the future, he would enjoy less literary success, and struggle to overcome near bankruptcy (the result of business failures and personal extravagance) with something of the same mettle that Grant showed in 1884-85. Also in Clemens' future were the deaths of his wife and two of his three daughters (they had already lost a son), which left a deep sadness over his last years.