Country tag for United States is:
USA
If you want play for United States HOI4 you could use tag command:
tag USA
To annex United States in HOI4 you could use annex command:
annex USA
To delete all United States units you could use deleteallunits command:
deleteallunits USA
To add interests on United States you could use add_interest command:
add_interest USA
To remove interests on United States you could use remove_interest command:
remove_interest USA
To start occupation on United States you could use occupationpaint command:
occupationpaint USA
More country tags for HOI4 or more cheats for Hearts of Iron IV