Political and economic unrest in the Arab world have sent gas prices skyrocketing in the United States in recent weeks, and some lawmakers are ready to tap into the country's Strategic Petroleum Reserve. What is that, and how much oil is in it? The reserve was formed after an energy crisis of a different era. In October 1973, the Organization of Arab and Petroleum Exporting Countries (OAPEC) shut off oil supplies in response to United States support of the Israeli military during the Yom Kippur War. The oil embargo, which lasted until the following March, caused a global energy and economic crisis. To prevent such a situation from arising again, the U.S. government created the Strategic Petroleum Reserve (SPR) in 1975. Several other countries also created oil reserves, but the American stockpile was and remains the biggest.