Battle of Tulifinny-- Part 3: The Only Time In History An Entire Student Body of a U.S. College Engaged in Combat

From Wikipedia

Fought December 6-9, 1863, in South Carolina during Sherman's March to the Sea, also known as the Savannah Campaign.

Outnumbered 5 to 1, a Confederate force successfully defensed a critical section of the Charleston-Savannah Railroad allowing troops and supplies from Savannah to be evacuated.

The battle was historically significant because it was one of the rare occasions when the United States Marine Corps fought in combat during he Civil War.  (I don't know about that.)  In addition, the Confederate force also included the  entire Corps of Cadets from the South Carolina Military Academy in Charleston, now the Citadel.

More than a third of the Confederate force was comprised of the Citadel Corps of Cadets and it was the only time when the entire student body of a U.S. college fought in combat.

In a Nutshell.  --Old Secesh