It took Grant a year to conquer Vicksburg. Federals had 125k troops at Corinth after Shiloh. They should of gone to Vicksburg then. John Sherman saved Crump. Washburn saved Grant.If Grant had lost Shiloh, he may well have been sent West like Pope or shelved like McDowell. Grant won Shiloh and was demoted! What would happen if he lost?
Halleck dumped Grant but fortunately Lincoln was wise enough to bring him back. Who would have replaced him that could have organized and attack Vicksburg in his place? Would not have been Sherman as he would have been tarred and feathered like Grant.
So if Shiloh saved Grant’s career then it may lay claim to the title The Battle that Won the War
Federals are pushed off of the Peninsula. Lost 1st and 2nd Manassas. Bragg goes to KY, Lee to Maryland. High water mark of the Confederacy was probably just before Antietam. So, several things could have happened during this period to secure Southern Independence.
People make the argument Sumpter turned the tide. Shiloh was important. A Confederate victory wouldn’t have secured a Confederate Independence. Most of these battles were a near stalemate. Yankees thought that Shiloh was the beginning of the end. They had suspended recruitment. Confederacy lasted a long time after losing the Mississippi River. Some argue that losing Vicksburg was a net gain for the Confederacy. It opened up trade. Cotton trading gave the Confederacy money and war material. All of that made the war last longer..