GDG- 4th PA Cav on July 2

[cameron2 at optimum.net]

<< Have you read my article on this very topic that was in issue 37 of  
Gettysburg Magazine?  My research indicated that the 4th PA did not  
arrive until just before Longstreet launched his assault, which would  
be sometime between 3 and 4 in the afternoon.  By then, it was far too  
little, far too late.

Here's what I wrote: "Gregg sent the 4th Pennsylvania Cavalry.  Its  
numbers were insufficient to cover the entire flank, and it is unclear  
when these men arrived in the area.  The Pennsylvania horse soldiers  
had come to Gettysburg by way of Hanover after an all-night march, and  
they were exhausted.  By the time they arrived, it was too little, too  
late, as Longstreet was about to unleash his sledgehammer blow on the  
Army of the Potomac's left flank. >>

My sense of the matter is that once the attack was in progress, the area was not a very good place for a cavalry regiment to be.  The regiment was probably in the position of trying to make itself useful around the periphery without getting clobbered in the process. 

Of course, I'll defer to Eric as to what they actually did.    :)