The explanation for this latest pop bio of the prodigious J. P. Morgan (1857-1913) is that previous biographers didn't sufficiently emphasize his loss of Mimi, the tubercular wraith he impetuously and hopelessly married--""the one blow the dexterous and adaptable young banker was never to recover from."" Jackson (Inside Monte Carlo, Monsieur Butterfly, etc.) adds only empty words to the poignant episode, however, not evidence or insights; Morgan's recurrent spells of despondency, related also to his bouts of ill health (and disfiguring attacks of acne rosacea), are part of the Morgan canon. We are told, in addition, that Jackson discovered Morgan not to be ""the all-conquering financial genius"" of legend; but these ""gross errors of judgment""--like eventually losing Charlie Schwab to rival Bethlehem Steel--pale alongside Morgan's accomplishments: the railroad mergers, the government-financing, the formation of the world's largest corporation (among others). Jackson's concluding determination--that Morgan had no regard ""for significant social and political change""--could hardly be more beside the point. The text dilates upon Morgan's distant and immediate forebears, his Hartford-and-Boston childhood and cosmopolitan youth--and, for no discernible reason, on the philanthropies of his father's London banker-partner, George Perkins. To the detriment of anyone seeking to understand Morgan or his career, it constantly mixes business, personal, and art-collecting detail--not even telling the classic story of the Carnegie buy-out, and the formation of US Steel, straight and whole. (The detail--cf. Carnegie's terms--doesn't reliably reflect what occurred either.) The personal judgments are crude: ""there is little doubt that he compensated for his disfigurement with abnormal amorous gusto and a sadomasochistic urge to be seen with and master beautiful women."" (The account of his falling-out with the social-reform rector of St. George's is both crude and unreliable.) Through to Morgan's celebrated appearance before the Pujo Committee, there is nothing here that hasn't been recounted better elsewhere--including Andrew Sinclair's wobbly Corsair (1981). Still far-and-away the best is Frederick Lewis Allen's vigorous, interpretive life.