In opposition to all the other answers here, I’m going to give.a qualified YES.
Late in life, Lee said the following:
“The biggest mistake in my life was taking a military education.”
What? The biggest mistake in his life? Can you imagine any victorious general, satisfied they were fighting for the right side, saying this? Or can you even imagine a defeated general, still certain of the rightness of his cause, saying this? Of course not.
It is an odd thing to say, and it requires a little unpacking. Lee’s problem was that, having graduated from West Point and choosing a military career, was going to have to fight for one side or another. And that presented him with a terrible dilemma. Having taken an oath to the US government, and having even served successfully as an officer (in the Mexican American War), he knew that he was, in some sense, a traitor to the organization he’d sworn to uphold.
But the other side of the dilemma was bad, as well. As the other answers have pointed out, to fight for the Union would’ve meant he’d be fighting against all his relatives and friends in Virginia. So, despite his living literally a stone’s thrown away from Washington DC, and therefore practically being on the “border,” he fought for the South.
I believe his statement was an admission that he he’d had no good choice from his point of view. Never forget that he was opposed to secession and therefore fought for the South reluctantly. The following quote shows that — although he felt his highest loyalty was to Virginia — he thought there was “no sufficient cause for revolution.”
On April 20, 1861, Colonel Robert E. Lee resigned from the United States Army in the midst of the secession crisis and the coming of the Civil War. “If Virginia stands by the old Union,” Lee said, “so will I. But if she secedes (though I do not believe in secession as a constitutional right, nor that there is sufficient cause for revolution), then I will follow my native State with my sword, and, if need be, with my life.”
Consider what’s going on here…. This is the statement of a man who is fighting for his “side,” Virginia,” but with misgivings.
And consider human nature. After a person chooses sides, for whatever reason, he has an overwhelmingly strong tendency to find reasons why it was the right decision: that is, to rationalize it. I’m sure that in the height of the Civil War, when he had already made a commitment, Lee had to tell himself he was on the right side. Otherwise, to kill so many in the defense of a bad cause would’ve been unconscionable to him.
BUT…. in his years of retirement, when he gave up the sword, was president of a college, and had a lot of time to think about it, I believe that his conscience re-asserted itself, and he realized that his life, in some sense, had been committed to a tragic mistake.
I’M GLAD THIS DAMN AFFAIR IS FINALLY OVER…