In the Civil War, his anger carried weight (6)
I believe the answer is:
ireton
'in the civil war' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'anger carried weight' is the wordplay.
'anger' becomes 'ire' (ire is intense rage).
'carried' says to put letters next to each other.
'weight' becomes 'ton' (unit of weight).
'ire'+'ton'='IRETON'
'his' acts as a link.
Can you help me to learn more?
(Another definition for ireton that I've seen is " General".)