The Revenue Act of 1932 contained a provision for the first federal gasoline tax of one penny per gallon.  In 2005, the federal gasoline tax was set at 18.4 cents per gallon and 24.4 cents per gallon for diesel fuel.  Additional state-mandated gasoline taxes range from 10 cents to 33 cents per gallon, bringing the national average tax on a gallon of gasoline bought in the U.S. to 42 cents.

Bonus Question:
Which was the first state to impose a tax on gasoline?
Answer:  Oregon, in 1919