The worst part of how history was taught in the past is its "Great Man" bias. Grant was maybe the fourth best general of the Union side, behind Sherman, Thomas and Sheriden, and those are three I come up with off the top of my head.
Since the industrial revolution, the side with the greater economic capacity usually wins. The North was going to win that war regardless of Grant. The war had been won when the North was 30 years ahead of the South in production capacity, and had a larger population. Furthermore, societies based on slavery or serfdom generally do poorly in extended wars.
The most interesting aspect of the Civil War was why the South continued to fight after July 4, 1863 when it was apparent that the South had no path to victory. This on top of the fact that the South was trying to maintain a socio-economic structure that benefitted about 5,000 Southern families and no one else. None of that was not covered in the Grant book.