I read that after the battle of Gettysburg there were so many dead bodies in shallow graves that the area for miles around stank of death for months and months. Can you imagine having to bury thousands of stinking bodies because that battle was in July and the bodies would have begun to decompose immediately? They did not have bulldozers or machines to dig. Someone had to dig graves. I imagine the confederate dead were just buried in trenches. I say this because the victors are never that kind to enemy dead even in modern times bodies are left to rot in the field.