The Battle of Shiloh, which began on this day in 1862, is a fascinating battle, not only for what did happen, but for what did not happen.
What did not happen was Grant and Sherman being cashiered out of the service. Grant was largely saved by two things. First, and most importantly, he managed to eke out a narrow win despite the disaster on the first day. Secondly, and nearly as importantly, his stock was still high because of his stunning victories at Fort Donelson and Fort Henry. Absent both of these facts he would have joined the long list of failed Union generals. Sherman's fate was tied to Grant's and without Grant there's little chance he'd have gotten his high commands.
Given how important Grant was for the successful outcome of the war, it's a reasonable question to ask if the Union would have been saved without him. It wasn't just Grant's field leadership, which resulted in the capture of THREE rebel field armies, but his strategic vision which coordinated ALL the Union armies in 1864 and 1865 to achieve ultimate victory.
Yet it all could have come to a sorry and quick end that April day at Pittsburgh Landing. The survival of Grant's reputation wasn't the only thing at risk. Grant's personal survival was also an open question. Quite a few generals fell on that field, including the opposing army commander.
One can play the what-if game with any battle of course, but there are some battles that seem to have turned on the twists of fate in a particularly profound way. Suppose a French cannon ball had taken Wellington's leg at on the field of Waterloo instead of Lord Uxbridge? Suppose the Enterprise's dive bombers had missed finding the Japanese carriers at Midway like the Hornet's? Suppose the HMS Hood had lasted another 15 minutes in its battle with the Bismarck?
And so I think Shiloh's real story is the second chance that it gave Grant. He lived through the first day -- which he screwed up royally -- and barely held the field. He was then able to drive the worn-out CSA army away. This is not to disparage Grant's personal qualities. Almost alone among top Federal commanders he had the moral strength to recover from a disaster -- but it was a disaster.
I don't have too many games on the battle. There's a scenario in Battle Cry depicting the fight around The Hornet's Nest, I have the Dixie: Shiloh collectible card game and the Blue & Gray quad game on Shiloh. While none are definitive simulations, they do provide some flavor of the drama around the battle and all have hit the table.