Unfortunately for the soldiers involved, the military commanders of the day, especially the older ones like Lee, were still using the tactics of direct assault that had been in use for centuries. The Civil War was a watershed for new equipment (subs, gatling guns, repeating rifles) as well as an evolution in tactics to manuver and total war.
The most masterful ( and hence successful)use of tactics during the war was Sherman who used the flanking manuver against Joe Johnston over and over, moving ever closer to Atlanta and the sea. He was truly the tactical innovator of the war--Damn his Yankee soul to hell :-)
LOL
Sheridan too.
Sheridan combined fast moving cavalry with quick moving infantry, similar in many ways to what Jackson did early in the war with just infantry....
I think Lee was also influenced by the fact that he'd won so many battles against superior forces. He'd begun to think his soldiers were divinely inspired and able to do anything he asked of them. What a bitter lesson it was to realize and accept the error in his thinking. And what a fine man he was to accept the responsibility so completely. I'd like to have known him.