Doyle,
Read item "24". Apparently it did not happen during Grierson's Raid
http://books.google.com/books?id=P3GCfNndaXcC&pg=PA157&lpg=PA157&dq=jefferson+military+academy+and+grierson%27s+raid&source=bl&ots=DfoBhAzpka&sig=-5OIn5Rv3LqMq5-CL5WmPfSvkJU&hl=en&ei=p6ikScrnCpDQnQef-PSgBQ&sa=X&oi=book_result&resnum=9&ct=result
I do love that scene, as well, always reminds me of the VMI boys at New Market. Of course, the VMI cadets were, for the most part, older and the fighting was much harder.
Jim