Old poet a big hit in the States (5)
I believe the answer is:
homer
I believe this clue is a double definition.
'old poet' is the first definition.
(ancient poet)
'a big hit in the states' is the second definition.
(home run in baseball)
(Other definitions for homer that I've seen before include "successful run in America?" , "Epic poet - score at baseball - kind of pigeon" , "Weak official" , "Great Greek poet who sometimes nods" , "Pigeon; classic writer" .)