the main source of income or u can say earning for USA is from taxes....taxes in USA r very much high and most of the us citizen pay it with their full concious. there r other factors which yield money for usa other than taxes are:
International trade
Tourism
Selling weapons and airbuses.
USA is rich in resources that's why their economy is on a boom, but now a days economy is moving towards fastly growing countries like china, India etc.
Taxation
Wood
The most important source of political power for the US government is the people.
The main source of fish is the Mercury fish. The Mercury fish is a tainted fish found widely in the US streams.
Taxation
most likely, it's coal
most likely, it's coal
The US Constitution.
Corn.
The US Constitution.
The US Constitution.
an energy source