You are quite right that Brandy Station was not a Union victory. It was most certainly a Confederate victory by the standard of the day. The Confederates were left holding the field, while the Union troops retreated. Mr. Hall's premise seems quite bizarre really and can only be a provocation to try and build interest.

He states at one point, "I herein contend there are four clearly identifiable (but related) reasons confirming that the Battle of the Brandy Station represents the “beginning of the end of the war.” Perhaps from his perspective, but this would only be true to those that buy into the "High Water Mark" moniker for the Battle of Gettysburg. I for one do not and nor did the men that fought the battle. The Pennsylvania Campaign is an enigma and the Confederate motives for entering Pennsylvania are not well understood or articulated. He demonstrates his lack of understanding when he goes on to state, "And is there anyone here who does not believe if Lee triumphed at the “little copse of trees,” that the Army of Northern Virginia would have incrementally and successfully invested Philadelphia, Baltimore and Washington during the following days?" Lee had no intention of attacking Philadelphia, Baltimore, or Washington!

I will repeat much of what I posted on October 16th. After the decisive Confederate victory at Chancellorsville in May 1863, the two armies took up positions on the opposite sides of the Rappahannock River. Then, in June 1863, General Lee quietly withdrew most of his forces and headed north into Pennsylvania.

By June 23, 1863, the van of the Confederate Army was in Chambersburg, PA, with the rest of the army at about Harper's Ferry and moving north. The Union Army was still entirely south of the Potomac River and it would be June 25, 1863, before the first elements moved into Maryland. By then, almost the whole Confederate Army were in Pennsylvania enjoying the bounty of the unspoiled land.

By June 27, 1863, Rodes and Johnson were in Carlisle, with Early entering York. The Union Army was still around Frederick/Middletown, Maryland. Three days later, the lead elements of the Union Army entered Gettysburg.....and the rest is history!

Why did Lee do nothing for three days? If his plan was to attack Harrisburg (as most Pennsylvanians thought, according to the newspapers) he had ample opportunity. If his plan was to attack Washington or Baltimore from the north, Early's troops were in position to initiate such a plan no later than June 28, 1863. But Lee did nothing! He sat and waited for the Union Army to make contact and then he engaged in a battle he supposedly wasn't really committed to initially.

The reason Lee did nothing was because he had already accomplished most of his objectives and resolved to consolidate his forces around Cashtown and await battle. This is confirmed by the following posted by David Upton:
On the evening of the 27th Lee had heard Hooker had crossed the Potomac, and was advancing by way of Middletown, and he, Lee, took measures to concentrate his forces, and ordered Ewell to move his troops back to Chambersburg; but on reflection, the order was modified. "In the absence of cavalry," says Lee, "It was impossible to ascertain his [the enemy's] intentions; but to deter him from advancing farther west, and intercepting our communications with Virginia, it was determined to concentrate the army east of the mountain." Longstreet thought that this would "draw [Hooker] into battle, in keeping with the general plan of the campaign and at the same time draw him off from the travel of our trains," and so advised Lee. Lee thought so too, and directed Ewell, if practiable, to move to Heidlersburg; and then, either directly to Cashtown, or by the turnpike at Gettysburg. "The advance of the enemy to the latter place," Lee says, "was unknown, and the weather being inclement, the march was conducted with a view to the COMFORT OF THE TROOPS." [a slower march]
"The Story of the Civil War, Livermore, 1933.

The Battle of Gettyysburg, although premature from Lee's perspective, was an expected and desirable outcome of their march into Pennsylvania. He could not possibly have intended to continue on to Baltimore or Washington, unless the Union Army withdrew in that direction. He was not going to abandon his supply lines or risk the interruption of the flow of supplies back into Virginia.

One would have to conclude that the campaign was a success from the Confederates' point of view. They were able to garner much needed supplies including thousands of head of cattle, they brought the war to the people of the North, and they dealt a serious blow to the Union Army. Serious enough that they were able to withdraw in an orderly fashion with little molestation.

The Battle of Brandy Station had been the first battle of the reorganized Union Cavalry Divisions. This reorganization was successful in halting the dominance of the Confederate Cavalry in the war. However, it seems that General Lee was cognizant of this fact and modified his tactics to compensate. After Gettysburg, the Confederates fought the rest of the war from a defensive position (read "Attack and Die" by Grady McWhiney and Perry D. Jamieson) with little dependence on the success of the Cavalry in battle. For this reason, Mr. Hall's conclusions of the importance of the emergents of the new and improved Federal Cavalry is wrong. Lee's new tactics neutralized any Union advantage.