He was Lincoln’s first choice to lead the Union army.
This whole thread is way too subjective. You can’t really have on true great field general or field marshal.
If you only take W.W. II into account, there were several outstanding field generals, many you don’t even know as they didn’t get the press others got.
Go below MacArthur, Patton, Montgomery, and even Bradley and you will find a number of excellent field generals that could and should have had more credit.
You can’t pick the Civil War and then say that Lee was the absolute best General for the ages in American History, it just isn’t so.
One can make a good case that top Generals like Pershing and Washington were pretty good, but below them are others worth of consideration.
I would say George Washington our first President.
Maybe Patton or Eisenhower?
No; he lost the Battle of Gettysburg. After that debacle the South had no chance to win a negotiated settlement.