H.W. Brands notes in his sources section that more than 100 biographies of Ulysses Grant have been published, in addition to countless studies of the Civil War. Could there really be anything new to say? "Of course," any seasoned biographer will reply. New sources, even on perennial subjects, are almost always discoverable -- not to mention changes in perspective that develop as new evidence comes to light.

The 31-volume edition of Grant's papers was completed only in 2009, and it includes letters and other supporting material that offer new insight into Grant's presidency, "in particular his campaign against the Ku Klux Klan," Brands explains. Indeed, what is distinctive about this distinguished biographer's new work is its rehabilitation of President Grant, who was not only a great general who wrote memoirs worthy of comparison to Julius Caesar's, but a great moral leader who pursued Lincoln's agenda of re-unifying the nation and integrating its former slaves into one indivisible nation.

Grant believed in the egalitarian ideals of the Fourteenth and Fifteenth Amendments, but his effort to follow through on Reconstruction was thwarted, Brands writes, by Southern Democrats, who "forgot that secession was about slavery," and "recast the Civil Was as a difference over states' rights," treating Reconstruction like a "carnival of corruption." The intrepid Grant confronted his opponents head on, embarking on a speaking tour during which he not only praised carpetbaggers, but called himself one, too. "Americans had long picked up and followed opportunity," Brands reports Grant as saying. But this view was drowned out by sentimentalization of the Old South and slavery.

History is often written with one eye focused on the present, and there can be no doubt that Brands' biting paragraphs are aimed at our current political climate: "The Northern capitalist Republicans lost touch with the anti-slavery roots of their party, they pushed aside Lincoln in favor of J.P. Morgan and his company, and if they didn't actively embrace the Southern redefinition of the war and its aftermath, they didn't bother to dispute it. They transmuted the Fourteenth Amendment from a charter of citizenship rights into a guarantor of corporate rights; the Fifteenth Amendment they and their Southern allies-in-amnesia ignored."

To turn history away from civil rights, Grant himself had to be degraded, stories of his drinking exaggerated and connections to scandals for which he bore no responsibility concocted. Part of the trouble, too, is that Grant's battles on behalf of Indians and his support of minority rights could not be won "against majority hostility or indifference," Brands concludes. For this biographer, Grant is the president of good intentions, waging "a good and honorable fight."

Carl Rollyson is the author of "American Biography," "Hollywood Enigma: Dana Andrews" and a forthcoming biography of Sylvia Plath (February 2013).