"I think Ulysses S. Grant is vastly underrated as a man and as a general. I know people think this and that about his drinking habits, which I think have been exaggerated way out of line. The fact is, he never demanded more men or material from the war department, he took over an army that had a long history of retreating and losing. That army had no confidence in their fighting ability and Grant came in as a real outsider. He had so many disadvantages going into the 1864 campaign, now 100 years ago. But he met every test and rose to the occasion unlike Ive ever seen in American history. He was a very tough yet very fair man and a great soldier. Hes not been given his due. Grant devised a strategy to end the war. He alone had the determination, foresight, and wisdom to do it. It was lucky that President Lincoln didnt interfere or attempt to control Grants strategic line of thinking. Lincoln wisely left the war to Grant, at least in the concluding moves after he came east. Grant is very undervalued today, which is a shame, because he was one of the greatest American generals, if not the greatest." - Dwight Eisenhower, July 1964.
Being underrated doesn’t make him the greatest if he’s tweaked in rating.