Pickett's Charge: Lee's greatest blunder
Lee's lieutenant, James Longstreet, warned against the attack, correctly perceiving that the advancing Confederates had no chance of succeeding and that a slaughter was in the offing. Several of Lee's other subordinates agreed with Longstreet, who argued that the Army of Northern Virginia should instead move around the Union left and place itself between the Army of the Potomac and Washington, forcing Gen. Meade to do the attacking and take the massive casualties.
In fact, Meade had originally preferred a defensive line along Pipe Creek in Maryland which was an even stronger position than the Union troops held at Gettysburg, and had the Confederates managed to slip past the Union left by night, they might have occupied it. If they had, the subsequent history of both the war and of the nation might have been much different.
But Lee persisted in the greatest blunder of his brilliant career, and the rest is history.
Thoughts from the aptly-named Carl M. Cannon here.
HT: Real Clear Politics