"Pop Tarts, root beer and funnel cakes" Well, maybe. What folks eat at events are specific to the unit and also the event; if that makes any sense. There are some events where anything goes, literally. And even within those events, there will be participating units that will do their very best to stick to a period menu; be it garrison style or field food. Then, there's events where an event organizer went to the archives and pulled out the Quartermaster Records and everyone eats only what was issued at that particular time, the event represents, in history.
The short of it is, there's no real answer to your question.
"Grumpy" Dave T.
"Yet, despite these small numbers, Kernstown was one of the most decisive engagements of the war. The Confederates, Under Jackson, though soundly defeated, ultimately lost the most. As historian Bruce Catton observed: ‘The victory meant nothing at all, whereas the mere fact that the battle had been fought meant a great deal.’ Indeed, the ramifications of this odd little affair reached all the way to President Lincoln."