I am going to add this from another thread I wrote on.... Go Grant!.
Everyone wants to criticize Generals for frontal assaults in war against entrenched positions. I want to point out in Grant's time he had basically three choices when he met an entrenched enemy on the battlefield. The choices were frontal assault or flanking them or withdrawing from the field. These are the choices any general had through the ages, up until the last years of WW one. I think we all and historians need to understand this dilemma faced by Grant and the other generals came before and after him, until WW one. How do you remove an entrenched opponent before you?
Grant did not have creeping artillery barrages, or bombers, or tanks at his use. He only had primitive artillery and bodies. It took WW one to show us you need hydraulic artillery, bombers, tanks and bodies working together to take an enemy's entrenched position. Grant had nothing but bodies...
I think Cold Harbor true sadness and surprise to everyone was not the loss of life but how fast it took to thousands of men. It took like or less than 20 mins to kill all those men and I think that had never been seen before. I think that is what is lost in the conversation. Industrial warfare arrived on the fields of Cold Harbor for the first time instead of a day of fighting it took minutes to kill thousands. It shock everyone... It is one of those moments in history that you can mark where the world was changed forever that we man lived in a new world after those less then 20 mins.
Back to Grant his goal was to crush Lee's army so withdrawing was not available or flanking. He had Lee in front of him so like Lee at Gettysburg, he attacked but learned that warfare had changed overnight... Have you ever ask why Grant keep extended his lines at Petersburg? History says he was always trying to flank Lee may so but Grant know he was thinning
Lee's ranks so Lee could not concentrate his forces in any one spot. It is one of reasons why there was no blood bath when Grant forces smashed through Lee's lines at Petersburg. I can argue Grant figured out how to fight trench warfare after Cold Harbor. Think, he thinned out Lee's lines and kept pressure on the flanks. so Lee could not concentrate his forces against Grant... Remember, it was the shortness of time it took to kill so many was the shock at Cold Harbor not the number deaths...