Supporter of general uprising when accepted (5)
I believe the answer is:
easel
'supporter' is the definition.
'general uprising when accepted' is the wordplay.
'general' becomes 'lee' (Robert E. Lee - US revolutionary commander).
'uprising' says the letters should be written backwards.
'when' becomes 'as' (**).
'accepted' is an insertion indicator.
'lee' back-to-front is 'eel'.
'eel' enclosing 'as' is 'EASEL'.
'of' is the link.
(Other definitions for easel that I've seen before include "Constable's supporter" , "stand supporting artistic effort" , "art supporter" , "Standing supporter" , "Picture frame" .)