Les, as a reenactor, I have never been asked "is that a real fire?" but a lot of others have. A friend was musing on why people would ask such a ridiculous question. Her theory was that people are so used to seeing Pretend Things in the Movies and on Television, and the know the Civil War battle they're about to see is Pretend, so the fire must be too. And the food. And the tent you sleep in. And the baby in your arms. And your hairdo.

Personally, I think we went to the moon, I think John Wilkes Booth was shot dead, as was Jesse James, and I don't believe Thomas Jefferson had Meriwether Lewis murdered. Haven't made up my mind yet about Roswell or the Kennedy assassinations. :-)