*CHARLOTTE, NORTH CAROLINA
August Jam, the largest concert in North Carolina history, took place at the Charlotte Motor Speedway on August 10, 1974.

Headlining acts included the Allman Brothers Band, Foghat, the Marshall Tucker Band, and Black Oak Arkansas.

WAYS radio station and other local sponsors, expected 70,000 concertgoers but widespread gatecrashing raised audience totals to over 200,000 (some reporting as high as 300,000), accidentally making it the largest concert in state history and at the time, the largest concert (not festival) in U.S. history. By comparison, August Jam drew half the crowd of Woodstock in 1969.*

https://identitydixie.com/2024/11/28/part-1-slavery-or-states-rights/

Before providing Longstreet's answer, it's important to caveat what he said. Many consider Lee's greatest victory--and hence his best battle--to be at Chancellorsville in May 1863, and for good reason. Though Longstreet was not present there, so he gave a contrary (and I think, correct) answer: Second Manassas. Here is what Longstreet had to say in full about that battle and why he considered it Lee's best, partly because of his own performance there.
"Well, perhaps the second battle of Manassas was, all things considered, the best tactical battle Gen. Lee ever fought. The grand strategy of the campaign also was fine, and seems to have completely deceived Gen. Pope. Indeed, Pope failed to comprehend Gen. Lee's purpose from start to finish, and, on August 30, when I was preparing to push him [Pope] off the Warrenton pike, he still imagined us to be in retreat, and his most unfortunate movements were based on that false assumption. Had Pope comprehended the true situation as early as the afternoon of August 28, as I think he ought, it might have gone hard with Jackson before I arrived. Pope was outgeneraled and outclassed by Lee, and through improper dispositions his fine army was outfought. Still, it will not do to underrate Pope; he was an enterprising soldier, and a fighter. His movements in all the earlier stages of the campaign were excellent for his purpose to temporarily hold the lines first of the Rapidan and then the Rappahannock. In the secondary affair with Banks at Cedar Mountain we had gained quite a success, yet Pope promptly concentrated and forced Jackson back again over the river."