Forty years ago, the OPEC oil embargo caused oil prices to skyrocket in the US. In order to keep American prices down, the U.S. Congress banned the export of crude oil. In 2015, with domestic production rising quickly, Congress voted to lift the export ban. What a difference a year makes. Exports have spiked, especially to Mexico and Canada. During the interim period (1994 – 2015) the US exported small amounts of oil due to loopholes in the export ban and through swaps, where refineries could import heavy crude to blend with domestically produced light crude and increase refinery efficiency.