The countries in North America each import and export different products. The United States exports to countries on every continent. Why is this possible?
The United States is rich in natural resources that can be used in many different ways.
The United States has access to railroads, making transportation cheap and easy.
The United States has power over other North American countries and regulates their trade.
The United States is centrally located and is closer to all the continents than any other country.