About three-quarters of the oil used in the United States comes from outside the Persian Gulf in the Middle East. That's due to large North American producers like the U.S. itself, Canada and Mexico. The U.S. is among the world's leaders in oil production.
Almost 40% of the oil we consume is produced here at home, primarily in Texas, Alaska, California, Louisiana, and Oklahoma.
For a breakdown of what we get for every barrel of oil: http://choosingscars.blogspot.com/2007/02/60-bucks-barrel-for-oil-from-opec-275.html#links