What was the deadliest/bloodiest single hour during the war? Over the years I have heard the Cornfield at Antietam, corinth and Pickett's Charge.... but what was it? From what i can gather it would be pickett's charge, nearly 10,000 casualties in 50 mins of fighting.
How many of that 10,000 were dead? Casualties, as you undoubtedly know, aren't just the dead but also include the wounded. And may also include POWs. The deadliest hour woud be in terms of just the dead while the bloodiest hour would be the dead and wounded. So it's possible for the Cornfield at Antietam to be the deadliest but Picket's Charge to be the bloodiest.
There's another way to measure that tragic data too...the deadliest based on the number killed compared to the number engaged. That would change the "deadliest" battles somewhat as opposed to measuring the sheer number of dead, regardless of how many combatants were actually engaged.
Another way to look at this picture is deadliest depending on the side. Some very deadly battles saw relatively few casulties and deaths on one side but a very high number on the other side.
You can get really compulsive and also research which battles resulted in the highest number of POWs. Or research which battles had the highest number of officers killed (or killed and wounded.)