State that USA incorporates after revolution (4)
I believe the answer is:
utah
'state' is the definition.
(Utah is a US state)
'that usa incorporates after revolution' is the wordplay.
'incorporates' says the answer is hidden in the clue.
'after revolution' says the letters should be written in reverse (letters revolve back).
'hatu' can be found hidden inside 'that usa'.
'hatu' reversed gives 'UTAH'.
(Other definitions for utah that I've seen before include "State of Western USA" , "American state associated with Mormons and their faith" , "The "Beehive" State, capital Salt Lake City" , "State founded by Mormon" , "US state, capital Salt Lake City" .)