By the end of the civil war

Amany confederate leaders had been tried for treason
BAfrican americans had gained full citizenship
Cthe south's economy had been destroyed
Dcongress had passed legislation to rebuild the nation

Verified Answer :

I'm pretty sure it is C
Reasoning:
It's not A because most Confederate leaders were pardoned.
It's not B because after the civil war, the South was forced to give citizenship to all Blacks.
It's not D because this too was during the reconstruction period after the civil war.