General Robert E. Lee ordered General Pickett (and against the advice of General Longstreet) to charge the Union Lines at Little Round Top in the Battle of Gettysburg. At roughly the same time, Confederate cavalry under the command of General J.E.B. Stuart attempted to get behind the Union lines to disrupt things if the charge succeeded.
As we all know, Pickett's Charge was a failure. The charge was, to my mind, a Napoleonic War charge against a well-positioned enemy equipped with rifled muskets and artillery. Pickett's division was shot to doll rags.
Stuart's attack similarly failed. In part, it was because he had fired two signal cannon to let Lee know he was in position, which alerted his enemy. Part of the Union cavalry forces in opposition was a brigade from Michigan commanded by Gen. Custer, whose cavalrymen were equipped with Spencer repeaters. They turned back the Rebs.
The following day, the siege of Vickburg ended when the Confederate garrison surrendered to the forces led by General Grant. The two battles, taken together, marked the turning point of the war. With fits and starts, sure, the tide was now flowing to Appomattox.
I have never understood the veneration of of General Lee. He lost his war. Losing at Antietam gave Lincoln the breathing space and the cover to issue the Emancipation Proclamation, which, among other things, drove a stake into the efforts by Confederate diplomats to gain formal recognition from Great Britain (or any other European nation).
Lee fundamentally misunderstood his task. He kept trying to hit home runs, get a knockout punch. But his job was to just keep the fight going until the Union gave up trying to beat the South. He didn't have to win, he had not not lose badly. Yet Lee kept rolling the dice on a grand victory and losing.
Add to that, Lee couldn't or wouldn't see the overall picture of the war. He fought as though all the mattered was the Army of Northern Virginia. He didn't seem to know or grasp that the losses in the west were strangling his cause. I don't know if he ever considered sending troops to oppose Gen. Sherman's attack on Atlanta and his march to the sea.
In fairness, Lee's army was badly equipped and badly fed. Desertion and draft evasion were epidemic in the Confederacy, especially after both widespread conscription and the "Twenty Negro Law" were enacted. Operation Anaconda eventually chocked off almost all foreign trade. The Confederate government didn't order farmers to grow foodstuffs instead of cotton, so warehouses were full of cotton that couldn't be traded to European merchants for weapons. Meanwhile, the Union both grew its own food and made its own weapons. In a war of attrition, most of the cards were held by the Union.
But all of the glorification of Bobby Lee is countered by one salient point:
He lost his war.