Where every figure came from
Congressional Research Service, The Strategic Petroleum Reserve: Background, Authorities, and Considerations (R46355), 13 May 2020 (text via EveryCRSReport.com) (The International Energy Agency and its stock rule; when the reserve may be used): https://www.everycrsreport.com/reports/R46355.html. Public domain (US government work). The 1973-74 embargo fostered the establishment of the International Energy Agency; signatories of its International Energy Program agreement must hold petroleum stocks equal to 90 days of the previous year's net imports, have programmes to restrain demand in an emergency, and take part in sharing oil deliveries to balance a shortage among members; net-exporting members have no stockholding obligation. Strategic stocks can help soften the market's reaction to a crisis or guarantee supply to some users. Congress's motivation in creating the reserve focused on a physical supply disruption; high prices alone are not an authorised reason for a release. In 1990 Congress amended the 1975 Act (P.L. 101-383) to allow releases for a domestic supply interruption, after the 1989 Exxon Valdez spill. Retrieved 1 October 2026.
Congressional Research Service, The Strategic Petroleum Reserve: History, Perspectives, and Issues (RL33341), updated 28 December 2009 (text via EveryCRSReport.com) (The argument over when to use the reserve, 1975 to 2009): https://www.everycrsreport.com/reports/RL33341.html. Public domain (US government work). The meaning of a "severe energy supply interruption" has been controversial, and the history of the reserve traces differences of opinion over it. After Iraq invaded Kuwait on 2 August 1990, the Bush Administration said it would not draw down the reserve without a physical shortage simply to lower prices; others argued that a perceived shortage does as much damage as a real one, and that releasing oil to calm markets is worthwhile in itself. Retrieved 1 October 2026.
Agency for Natural Resources and Energy (Japan), Annual Report on Energy (Energy White Paper) 2018, Part 1, Chapter 1, Section 4, "1970s and 1980s" (Japanese) (The IEA stock rule; Japan's stockpiling, energy-saving and oil-substitution laws): https://www.enecho.meti.go.jp/about/whitepaper/2018html/1-1-4.html. Japanese government web content; paraphrased in English. Section 3(1): the OECD recommended in July 1962 that its European members hold at least 60 days of oil, and in July 1971 that they hold 90 days; the European Community recommended 90 days in October 1971. Section 3(2): the IEA, set up in November 1974, required members to hold oil stocks of 60 days of net imports and to reach 90 days by 1980; in 1975 Japan enacted the Petroleum Stockpiling Act and began a plan to reach 90 days by the end of fiscal 1979; because of the Iranian revolution it was reached in fiscal 1980, one year late; holding 90 days was a heavy burden on oil companies, with interest costs raised by higher crude prices, and business repeatedly called for the government to lead further stockpiling; national (state) stockpiling began in 1978. Section 4: oil supplied more than 70 per cent of Japan's energy when the first oil crisis struck; the Act on the Rational Use of Energy was enacted and brought into force in 1979, covering factories, buildings and machinery, with standards for factories, records of energy use for factories above a set size and recommendations where efforts fell short. Section 5: the Sunshine Project (1974-1992) researched solar, geothermal, coal and hydrogen technology, aiming at new clean energy to meet a large part of energy demand decades ahead, with 2000 as its horizon; in 1980 the Act on the Promotion of Development and Introduction of Alternative Energy to Oil was passed and NEDO (the New Energy and Industrial Technology Development Organization) set up. Section 1(1): Japan's LNG imports were 5.01 million tonnes in fiscal 1975 and 16.97 million in fiscal 1980 ("more than tripled" is calculated by Ceteris: 16.97 / 5.01 = 3.39). The section headings tie the start of stockpiling and the energy-saving law to the oil crises. Retrieved 1 October 2026.
Energy Policy and Conservation Act, Public Law 94-163, 22 December 1975, 89 Stat. 871 (via govinfo.gov) (The law that created the Strategic Petroleum Reserve and set fuel-economy standards): https://www.govinfo.gov/content/pkg/STATUTE-89/pdf/STATUTE-89-Pg871.pdf. Public domain (US statute). Sec. 2: purposes include standby authority to ration and to reduce demand, meeting US obligations under the international energy program, a Strategic Petroleum Reserve, and better fuel economy of motor vehicles. Sec. 3(7): the Agreement on an International Energy Program was signed by the United States on November 18, 1974. Sec. 151 and 154: a reserve of up to 1 billion barrels, and not less than 150 million barrels by the end of three years from enactment. Sec. 161(d): no drawdown unless the President has found it is required by a severe energy supply interruption or by obligations under the international energy program. Sec. 301 (new Sec. 502(a) of the Motor Vehicle Information and Cost Savings Act): average fuel economy standards for passenger cars of 18.0 miles per gallon for model year 1978, rising to 27.5 for 1985 and after. Retrieved 1 October 2026.
Gerald R. Ford, Statement on the Energy Policy and Conservation Act, 22 December 1975 (Public Papers of the Presidents; text via The American Presidency Project) (Why Ford signed): https://www.presidency.ucsb.edu/documents/statement-the-energy-policy-and-conservation-act. Public domain (US presidential statement). Ford decided to sign; the bill is "by no means perfect"; it provides authorities he asked for in January, including a strategic storage system, emergency authorities in case of another embargo, and authorities to fulfil international agreements with other oil-consuming countries; the bill seeks to lower retail prices in the short term, but over time removes controls, and he intends to expedite decontrol of crude oil; he pledges that by the end of 40 months controls over domestic oil prices will be fully phased out; a veto would almost surely have continued the debate through the election year and beyond; the bill is the most constructive likely to be worked out at this time. Retrieved 1 October 2026.
Foreign Relations of the United States, 1969-1976, Volume XXXVII, Energy Crisis, 1974-1980, Document 89: Memorandum from Brent Scowcroft to President Ford, 10 December 1975 (Office of the Historian) (The case for signing and the estimates on both sides; who advised what): https://history.state.gov/historicaldocuments/frus1969-76v37/d89. Public domain (US government). Scowcroft recommends signing. Even under immediate decontrol US imports would be 8 million barrels a day at the end of three years, against roughly 9 million under the most unfavourable case for the bill; the stockpiling authorities would let the US begin building reserves promptly and lower its vulnerability to embargoes; the bill contains the authorities to carry out US commitments for sharing and conservation under the International Energy Program; Congressional attempts to relegislate rollbacks or controls, perhaps highly stringent ones, would create greater international uncertainty; the Council of Economic Advisers estimated that immediate decontrol would mean a 1.2 per cent decline in GNP and a 0.3-0.4 point rise in unemployment by the fourth quarter of 1976 (Treasury: 1.2 per cent decline in GNP in 1976 and 0.2 point rise in unemployment). Editorial footnote 2: Ford recalled in his autobiography that his economic advisers, Simon and Greenspan, advised him to veto the bill, while his political advisers and Federal Energy Administrator Frank Zarb urged him to sign. Editorial footnote 4: Ford signed on 22 December, and later called the bill "an inadequate measure" (A Time To Heal, p. 340). Retrieved 1 October 2026.
U.S. Department of Energy, Office of Legacy Management, Timeline of Events: 1971 to 1980 (The Federal Energy Office, the Federal Energy Administration and the Department of Energy): https://www.energy.gov/lm/timeline-events-1971-1980. Public domain (US government). 4 December 1973: the Federal Energy Office is assigned to allocate reduced petroleum supplies and control oil prices. 7 May 1974: the Federal Energy Administration replaces it. 22 December 1975: Ford signs the Energy Policy and Conservation Act, extending oil price controls, mandating automobile fuel economy standards and authorizing a strategic petroleum reserve. 4 August 1977: Carter signs the Department of Energy Organization Act. Retrieved 1 October 2026.
U.S. Department of Energy, A Brief History of the Department of Energy (Energy policy before the 1970s, and the department the crisis produced): https://www.energy.gov/lm/doe-history/brief-history-department-energy. Public domain (US government). Until the 1970s the federal government played a limited role in energy policy; no overall energy policy existed, and officials thought in terms of particular fuels rather than energy. The energy crisis of the 1970s hastened a series of reorganisations. The department, activated on 1 October 1977, brought most federal energy activities under one umbrella, including long-term energy research and development and energy conservation. Retrieved 1 October 2026.
U.S. Department of Energy, SPR Quick Facts (Where the reserve is kept, its first oil and its highest level): https://www.energy.gov/ceser/spr-quick-facts. Public domain (US government). Four sites on the Gulf Coasts of Texas and Louisiana, in caverns carved into natural salt domes. 1977: the first oil delivery, 412,000 barrels of light sweet crude. Highest inventory recorded: 726.6 million barrels, on 27 December 2009. The reserve is owned and operated by the U.S. Department of Energy. Retrieved 1 October 2026.
U.S. Department of Energy, History of SPR Releases (The four emergency sales and the countries that released oil alongside): https://www.energy.gov/ceser/history-spr-releases. Public domain (US government). The President has authorized emergency releases on four occasions. January 1991: the first-ever emergency drawdown, the US share under a coordinated emergency plan drawn up by the International Energy Agency, announced as allied attacks on Iraq began. September 2005: after Hurricane Katrina, part of a coordinated response with the IEA. June 2011: in response to the loss of crude oil from supply disruptions in Libya and other countries, with IEA partners. March and April 2022: the United States and 30 other IEA member countries agreed to release oil in response to Russia's war on Ukraine; DOE released 180 million barrels in total. Retrieved 1 October 2026.
U.S. Energy Information Administration, U.S. Ending Stocks of Crude Oil in SPR, thousand barrels, annual (series MCSSTUS1) (The episode chart: how much the reserve held at the end of each year, 1977 to 2025): https://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=MCSSTUS1&f=A. Public domain (US government). Thousand barrels, end of year; the chart shows millions. 7,455 (1977), 66,860 (1978), 91,191 (1979), 726,616 (2009), 593,682 (2021), 372,030 (2022), 354,684 (2023), 413,464 (2025); printed as about 67, 355 and 413 million. The share of the 150-million-barrel target reached by the end of 1978 (66.86 / 150 = 0.446) is calculated by Ceteris. The monthly series (f=M) shows 304,810 thousand barrels in July 2026, the latest figure; the chart stops at the end of 2025. Release date 30 September 2026. Retrieved 1 October 2026.
Council of Economic Advisers, Economic Report of the President, February 1974 (via FRASER) (US oil price controls before the 1975 bill, and dearer oil and output): https://fraser.stlouisfed.org/files/docs/publications/ERP/1974/ERP_1974.pdf. Public domain (US government). Printed page numbers. P. 22: the slowdown of output and of demand is intensified by the higher prices and reduced imports of oil. P. 33: imported oil, "new" oil and oil from small wells are exempt from control; other oil is controlled and sells well below uncontrolled oil. Retrieved 1 October 2026.
U.S. Department of Energy, The United States Energy Department Continues Execution of Strategic Reserve Release Commitments, 29 September 2026 (The 2026 release from the reserve): https://www.energy.gov/articles/united-states-energy-department-continues-execution-strategic-reserve-release-commitments. Public domain (US government). DOE issued a request for proposal for "an exchange of up to 40 million barrels of crude oil from the Strategic Petroleum Reserve (SPR), continuing DOE's execution of the 172-million-barrel release previously announced by President Trump in coordination with the International Energy Agency (IEA) member nations' overall 400-million-barrel commitment." Earlier solicitations "collectively awarded more than 133 million barrels across four completed exchanges"; companies return borrowed barrels "with additional premium barrels". The page does not give the month the release was announced. "Much of it lent to companies" is Ceteris's reading of the exchanges (133 million awarded plus up to 40 million offered, against 172 million). Retrieved 1 October 2026.
Richard Nixon, Statement on Signing the Emergency Highway Energy Conservation Act, 2 January 1974 (Public Papers of the Presidents; text via The American Presidency Project) (The 55 miles-per-hour speed limit): https://www.presidency.ucsb.edu/documents/statement-signing-the-emergency-highway-energy-conservation-act. Public domain (US presidential statement). The act aims at reducing gasoline and diesel use during the energy crisis; states' continued receipt of federal highway trust funds is conditioned on their setting maximum speed limits of 55 miles per hour; Retrieved 1 October 2026.
National Highway System Designation Act of 1995, Public Law 104-59, approved 28 November 1995 (via govinfo.gov) (The end of the national speed limit): https://www.govinfo.gov/content/pkg/PLAW-104publ59/html/PLAW-104publ59.htm. Public domain (US statute). Sec. 205(d): repeal of the National Maximum Speed Limit Compliance Program; Sec. 347 refers to "the repeal of the national maximum speed limit". Retrieved 1 October 2026.
Venice Economic Summit Conference Declaration, 23 June 1980 (Public Papers of the Presidents: Jimmy Carter, 1980; text via The American Presidency Project) (The seven leaders' plan to replace oil, and their request to the World Bank): https://www.presidency.ucsb.edu/documents/venice-economic-summit-conference-declaration-issued-the-conclusion-the-conference. Public domain (US Public Papers). Para. 7: break the existing link between economic growth and consumption of oil, in this decade, by conserving oil and increasing alternative sources. Para. 10: a large increase in the use of coal and enhanced use of nuclear power in the medium term, and more synthetic fuels, solar energy and other renewables over the longer term. Para. 21: the leaders ask the World Bank to examine the resources and mechanisms for exploring, developing and producing conventional and renewable energy in oil-importing developing countries, and how it might increase its lending for energy. Para. 34: the signatories are seven large industrialised countries. Retrieved 1 October 2026.
All wording is our own. Charts are drawn from the data named under them.