Unfortunately for Gen Grant and the Union side he served under self serving political Generals that suppress his battle field wins and attempted to take the glory for those wins on the battle field for them selves, and back stabbed Gen Grant. Fortunately for Gen Grant, Lincoln eventually seeing through those lies of his worthless generals on the western front and promoted the fighters like Gen Grant.
Halleck seems to have had in for Grant, when he was Grant’s superior in the Western theater.