Answers: The battle of Fort Stedman and battle of Five Forks
The two battles that proved to be the undoing of Lee’s attempt to protect Richmond in the latter days were the battle of Fort Stedman and Five Forks. Gen. Robert E. Lee combined half of his army in an attempt to break through Grant’s Petersburg defenses and threaten his supply depot at City Point.
However, his army were assaulted and captured, which had been weakened for the assault on Fort Stedman. Moreover, Lee’s army want to set up the confederate defeat at the battle of Five Forks.