With a Rebel Yell?

What did the "rebel yell" used by Confederate troops in the Civil War sound like? For years and years this question as been posed as mysterious and unanswerable. Historian Shelby Foote, appearing in Ken Burn's Civil War, said we could never be sure, going on to describe it as probably sounding like "a foxhunt yip mixed up with sort of a banshee squall." But it turns out we can know exactly what it sounded like, thanks to some early recordings at the Library of Congress: