Why was it so difficult to rebuild the south after the civil war

There's a variety of reasons.  After the war, the south was quite literally, war torn, meaning everything was demolished or burning to the ground. After a war, both sides don't suddenly start accepting each other, and the civil war is no exception, there was a bunch of resentment back then due to the calamities of war.

Explanation:

Screwed up time but necessary

they all focused on themes about the inevitability of death.

answer; repetitive thoughts; ritualistic behaviors;