Case in point
Ulysses Grant was a general of the American Civil War (1861-1865) who later served as President of the United States (1869–1877). By the 1920s, his reputation had fallen to a low point. Grant was seen as a drunken, bungling butcher who won his battles only by callousness and sheer weight of numbers. In this, he was seen as a forerunner of the generals of the Great War.
After World War II, there was a reconsideration of Grant's generalship. Grant's rise from humble beginnings was seen as a version of the American Story. His anti-intellectualism was contrasted with Euro-phile (and much less successful) generals who had preceded him, like George B. McClellan. Grant was therefore the epitome of the triumph of Yankee know-how over book learning. Grant's strategy and tactics were seen as revolutionary, pointing the way to total war. He became the prophet of the American Way of War, of the kind that had defeated the Japs and Nazis.
This came at a fortunate time for Grant, for the early 1960s saw celebrations of the centenary of the war, and Grant's reputation placed him on a pedestal, albeit one below that of his by now deified opponent, Confederate General Robert Lee, but a more than worthy and gallant opponent.
This idealist portrayal of the American Way of War started to decline in populatity in the late 1960s and by the 1970s, Grant's reputation had begun to slide again. His notorious order expelling Jews from Tennessee now re-appeared in the history books. But his reputation did not fall as much as formerly, and Grant still had his defenders.
Strangely, Grant is still seen as a general. His time as president has left little mark and his presidency, along with the Reconstruction as a whole, is still widely regarded as a scandal-ridden failure, there having been little effort at re-appraisal. Moreover, Grant the general is Grant the Civil War general; the campaigns against the Indians and against terrorists in the South after the Civil War are conventionally omitted.
Some saw General Norman Schwarzkopf's disastrous decision in the Gulf War (1990-1991) to allow Saddam Hussein's regime to continue using helicopters as a bungled emulation of Grant's magnanimous surrender terms at Appomattox (when he permitted Confederate officers to keep their horses and sidearms), but lacking in Grant's understanding of the politics involved.
Thus, while there is far from any shortage of books about Grant, a balanced appraisal still remains elusive.