September 17th, 1862 would be the single bloodiest day (Antietam). Gettysburg (July 1-3, 1863) would be the bloodiest battle with over 51,000 casualties in the 3 days.

Total American deaths were ~4,000 at Antietam (~3,700 plus later deaths). It should also be noted that deaths during the Civil War were mostly dead on the battlefield or shortly there after. The state of medicine (Civil War medicine prescribed mercury for some stomach ailments) was appalling.

Gettysburg had over 10,000 dead with another 10,000 missing in the 3 days of July 1-3, 1863. There was over 51,000 total casualties.

Both of these are considered campaigns. The Maryland Campaign of 1862 would have included battles at South Mountain and others. The Gettysburg Campaign included the fighting at Brandy Station (JEB Stewart took it on the chin there) as well as several other battles in the valley.

I just watched the "Grant" series so those names are still fresh in the mind.

At Shiloh, for instance, the CSA soldiers are buried in mass graves. The Union soldiers have a US cemetery in the Arlington style.

The deaths in the Civil War are all counted as American deaths. As a matter of fact, the Union was preserved, so they all were Americans (Play Dixie for them so that they can understand they can still play it under our rule. -- Lincoln 4/10/65 while leaving Richmond).

The mass graves at Shiloh were more of a consequence of the high temperatures. There was a request for a truce, but Grant had already ordered the burials. The graves are marked with cannon balls as a surround and interpretation to offer a bit more understanding. A couple of them are a bit off of the beaten path. FWIW, Shiloh is one of the more pristine battlefields. Due to its remoteness, it is not heavily visited and remains much as it was in April, 1862.

Campaign would be a more accurate term. There were three phases and numerous battles. One of its alternate names is "Battles of the Meuse–Argonne".

Even if we assume for a moment that it's a battle, it's not the deadliest battle in terms of American deaths. It's the deadliest campaign in the history of the US Army. Note the distinction. As others noted, there were more deaths at Gettysburg.

((sorry, still awaiting replacement computer mouse)

((I googled "one day America casualties" and found a Wikipedia page with "list of battles with most United States military fatalities".
It lists the highest one-day fatalities as either D-Day (2500) or the start of the battle of Saint Mihiel (12 Sep 1918) (possibly more). Union dead at the height of Battle of Antietam was listed as 2108. It also gives figures for both sides at Antietam and for the D-Day campaign..))

I believe her.....



I guess I shouldn't make light of this subject. My great-uncle was in the Meuse-Argonne offensive, and was a mental wreck as a result. My granfather only missed it because of pneumonia that got him discharged and sent home.

He left the US in 1914 to enlist in the British Black Watch, and was severely wounded with a silver plate replacing part of his skull.

He was a horrible father apparently, violent and often drunk and was murdered in a bar fight before I was born; I never met him.

It was at a family Fourth of July gathering, and we couldn't have fireworks because he reacted badly to things that went boom. My parents said he suffered shell-shock; today, we know it as PTSD, and he had a really bad case of it.