Go into American heartland, heading away (5)
I believe the answer is:
enter
'go into' is the definition.
(enter can mean to go into a place)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for enter that I've seen before include "put in for a race" , "Go in - set down" , "Come in - penetrate - record" , "Set foot in" , "Register formally as a participant" .)