Nuclear History Timeline

Pre 1940s

  • 1895 -Wilhelm Roentgen discovers x-rays. The world immediately appreciates their medical potential. Within five years, for example, the British Army is using a mobile x-ray unit to locate bullets and shrapnel in wounded soldiers in the Sudan.
  • 1898 - Marie Curie discovers the radioactive elements radium and polonium.
  • 1905 - Albert Einstein develops theory about the relationship of mass and energy.
  • 1911 - Georg von Hevesy conceives the idea of using radioactive tracers. This idea is later applied to, among other things, medical diagnosis. Von Hevesy wins the Nobel Prize in 1943.
  • 1927 -Herman Blumgart, a Boston physician, first uses radioactive tracers to diagnose heart disease.
  • December 1938 - Two German scientists, Otto Hahn and Fritz Strassman, demonstrate nuclear fission.
  • August 1939 - Albert Einstein sends a letter to President Roosevelt informing him of German atomic research and the potential for a bomb. This letter prompts Roosevelt to form a special committee to investigate the military implications of atomic research.

The 1940s

World War II ended the Great Depression of the 1930's. During the 1930's three totalitarian, militaristic powers had arisen in the world--Germany, Italy, and Japan. Germany, under Adolph Hitler and the National Socialist (Nazi) Party, invaded Poland on September 1, 1939, and Britain and France declared war upon Germany and its allies two days later. By the summer of 1940, the Nazi Blitzkrieg, or lightening war, had rolled over Denmark, Norway, the Netherlands, Belgium, and France, giving Germany control of most of western Europe. Italy declared war in June 1940, and invaded British and French Somaliland, Egypt, and Greece later that summer. Germany, Italy, and Japan signed the Tripartite Pact, making them allies, in September 1940. In the Far East, Japan had marched through China, reaching French Indochina (now Vietnam) by July 1941.

The United States, however, remained neutral until December 1941. Since the close of World War I, the United States had striven to isolate itself politically from what it saw as internal European problems. President Roosevelt announced, "This nation will remain a neutral nation, but I cannot ask that every American remain neutral in thought as well." The United States remained neutral in neither thought nor action. It sold surplus weapons and traded aging destroyers to the British in exchange for military bases.

  • December 1941 - Japan bombs Pearl Harbor. The United States enters World War I
  • September 1942 - The Manhattan Project is formed to secretly build the atomic bomb before the Germans. 
  • November 1942 - Los Alamos is selected as the site for an atomic bomb laboratory. Robert Oppenheimer is named the director.
  • December 1942 - Fermi demonstrates the first self-sustaining nuclear chain reaction in a lab under the squash court at the University of Chicago. Soon after, a complex of top-secret nuclear production and research facilites are built by the Manhattan Project across the country. 
  • 1942-45 - The Clinton Engineer Works is built in Oak Ridge, Tennessee. It is renamed the Oak Ridge National Laboratory after World War II. The Clinton Pile, the first true plutonium production reactor, begins operation in November 1943. By March 1945, K-25 and other gaseous diffusion plants are in operation. 
  • 1943-45 - The Hanford Site is built in Richland, Washington by the Manhattan Project to produce plutonium. The first reactor begins operation in September 1944.
  • February 1945 - Yalta Summit ratifies a divided postwar Europe. 
  • April 1945 - U.S. troops liberate Nazi concentration camp at Buchenwald. 
  • May 1945 - Germany surrenders.
  • July 1945 - The United States explodes the first atomic device at a site near Alamagordo, New Mexico.
  • August 1945 -The United States drops atomic bombs on Hiroshima and Nagasaki. Japan surrenders.
  • March 1946 - Winston Churchill proclaims an "iron curtain" has come down across Europe.
  • July 1946 - Atomic Energy Act (AEA) is passed, establishing the Atomic Energy Commission (AEC). The AEC replaces the Manhattan Project on December 31, 1946. The AEA places further development of nuclear technology under civilian (not military) control.
  • July 1946 - The United States tests a nuclear bomb on Bikini Atoll, an island in the Pacific. Four days later bikini swimsuit debuts at a French fashion show.
  • August 1946 - The Oak Ridge facility ships the first nuclear reactor-produced radioisotopes for civilian use to the Barnard Cancer Hospital in St. Louis. After World War II, Oak Ridge turns out numerous inexpensive radioactive compounds for medical diagnosis and treatment, and for research and industrial applications.
  • April-May 1948 - Nuclear tests in the South Pacific (Operation Sandstone) pave the way for mass production of weapons that previously had to be assembled by hand. By late 1948, the United States has 50 nuclear bombs.
  • June 1948 - The Soviet Union begins the Berlin Blockade, cutting West Berlin off from the West. The United States begins vast airlift to keep Berlin supplied with food and fuel.
  • May 1949 - National Chinese forces led by Chiang Kai-shek retreat from mainland China to Formosa.
  • August 1949 - The Soviet Union detonates its first atomic device.

The 1950s

In 1945, American troops returned home, many starting new lives and families. Between 1946 and 1964, 76.4 million baby boomers were born. Over 13 million homes went up from 1948 to 1958. Most were affordable, cookie-cutter houses fashioned after the phenomenally successful Levittown, Long Island. William J. Levitt had pioneered the suburb by building neighborhoods of nearly identical, quickly built housing. America's movement to the suburbs spurred the growth of shopping malls, drive-ins, and supermarkets. Many saw the 1950's as a return to prosperity and social "normality."

The prosperity and social normality was tinged with a "Red" hysteria, however. Americans saw communism on the march everywhere. By the end of the 1940's, Americans had seen the Soviets try to cut off Berlin from the West, Mao's Communist Party come to power in China, and the Soviet Union explode its first atomic bomb. In 1947, President Truman had outlined what became known as the Truman Doctrine: "I believe that it must be the policy of the United States to support free peoples who are resisting subjugation by armed minorities or by outside pressures." A State Department official, George Kennan, later fleshed out the Truman Doctrine, introducing the policy of "containment," which meant the United States would contain the Soviet Union's influence anywhere in the world. The "containment of the Communist threat" colored U.S. foreign policy decisions for decades to come.

At home, politicians found it politically expedient to be hard on communism. A former Communist Party member charged former Roosevelt advisor, Alger Hiss, with being a Communist spy. Hiss denied the charges before the House Un-American Activities Committee, which investigated alleged communist subversion in the U.S. government. The statute of limitations protected Hiss from espionage charges, but he was later found guilty of perjury. At the same time, Americans learned that respected Los Alamos scientist Klaus Fuchs had been passing atomic secrets to the Soviet Union. Other conspirators testified that they had passed the secrets to Julius and Ethel Rosenberg. The Rosenbergs were convicted and executed as spies. Their defenders--then and now--claimed the Rosenbergs were framed, convicted, and executed in an anti-Semitic and anti-Communist frenzy.

  • January 1950 - President Truman orders the Atomic Energy Commission to develop the hydrogen bomb (H-bomb).
  • February 1950 - Senator Joseph McCarthy launches a crusade to rout out communism in America. "McCarthyism" is born.
  • June 1950 - The Korean War begins as North Korean forces invade South Korea.
  • December 1951 - The first usable electricity from nuclear fission is produced at the National Reactor Station, later called the Idaho National Engineering Laboratory.
  • October 1952 - Operations begin at the Savannah River Plant in Aiken, South Carolina, with the startup of the heavy water plant.
  • December 1953 - In his Atoms for Peace speech, President Eisenhower proposes joint international cooperation to develop peaceful applications of nuclear energy.
  • January 1954 - U.S. Secretary of State John Foster Dulles announces U.S. policy of massive retaliation, that the United States would respond to any Communist aggression.

    The first nuclear submarine, U.S.S. Nautilus, is launched.

  • April 1954 - Army-McCarthy hearings are on TV for five weeks. By the end, Senator McCarthy is publicly disgraced.
  • August 1954 - The Atomic Energy Act of 1954 is passed to promote the peaceful uses of nuclear energy through private enterprise and to implement President Eisenhower's Atoms for Peace Program.
  • July 1955 - Arco, Idaho becomes the first U.S. town to be powered by nuclear energy.
  • October 1956 - Hungarian revolution is crushed by Soviet tanks.
  • November 1956 - Soviet Premier Nikita Khrushchev tells the West, "History is on our side. We will bury you."
  • July 1957 -The Sodium Reactor Experiment in Santa Susana, California generates the first power from a civilian nuclear reactor.
  • September 1957 - The United States sets off first underground nuclear test in a mountain tunnel in the remote desert 100 miles from Las Vegas.
  • October 1957 - Radiation is released when the graphite core of the Windscale Nuclear Reactor in England catches fire.

    The Soviet Union launches Sputnik, the first spacecraft.

    The International Atomic Energy Agency (IAEA) is formed to promote the peaceful uses of nuclear energy and to provide international safeguards and an inspection system to ensure nuclear materials aren't diverted from peaceful to military uses.

  • December 1957 - The first U.S. large-scale nuclear powerplant begins operating in Shippingport, Pennsylvania.
  • October 1959 - The Dresden-1 Nuclear Power Station in Illinois achieves a self-sustaining nuclear reaction. It's the first U.S. nuclear powerplant built entirely without government funding.

The 1960s

The civil rights movement picked up momentum during the 1960's. The movement started in the 1950's to protest segregation. In 1896, the Supreme Court had ruled that there should be "separate but equal" facilities for black and white Americans. The ruling dictated that everything from maternity wards to morgues be segregated. Though separate, segregated facilities, particularly schools, were seldom, if ever, equal. White schools were usually new and well-maintained while black schools were single room shacks. In 1951, the Reverend Oliver Brown tried to enroll his daughter, Linda, in all-white Sumner Elementary School in Topeka, Kansas. Denied, Brown sued the Board of Education, and the case was argued before the Supreme Court in 1953. In an unanimous decision, the Court ruled, "Separate educational facilities are inherently unequal." Brown v. the Board of Education ended segregation in public schools, but school systems in both the North and South fought the decision.

The civil rights movement began in earnest after 43-year-old seamstress Rosa Parks was arrested for refusing to give up her seat to a white person on a Montgomery, Alabama bus. The black community of Montgomery selected the minister of her church, Reverend Martin Luther King, Jr., to lead the protest against her arrest. King put his philosophy of non-violent civil disobedience into action by organizing a boycott of Montgomery's buses. For more than a year no black person rode a Montgomery bus. In November 1956, the Supreme Court ordered Montgomery to desegregate its buses. For the next ten years, peaceful protests led the civil rights movement slowly along until it boiled over in the mid-1960's.

In 1963, King led 250,000 people in a peaceful march on Washington, D.C. His televised "I have a dream" speech confronted white America with the justice of the civil rights movement. He said, "I have a dream that one day this nation will rise up and live out the true meaning of its creed: 'We hold these truths to be self-evident; that all men are created equal.'" In June 1964, the Civil Rights Act was passed, and in October, King won the Nobel Peace Prize.

By 1965, however, the tenor of the movement changed; it's nonviolence was being increasingly met with violence and death. President Kennedy and Mississippi NAACP (National Association for the Advancement of Colored People) leader Medgar Evars had both been killed in 1963. In 1964, a Birmingham, Alabama church was bombed, killing four little girls, and three civil rights workers were slain in Mississippi. Malcolm X, one-time spokesman for the Nation of Islam and leader of the Organization for Afro-American Unity, was murdered in early 1965. On August 11, 1965, a predominately black section of Los Angeles called Watts erupted in six days of riots. A white policeman had arrested a black motorist for drunk driving, and the gathering crowd's frustration erupted into violence. The summer of 1965 was the first of several summers that left cities smoldering with unrest, the worst rioting happening in Newark and Detroit in 1967. Presidential commissions studying the riots determined the cause was economic. Martin Luther King agreed, "I worked to get these people the right to eat hamburgers, and now I've got to do something to help them get the money to buy them." However, he was killed in March 1968, setting off another wave of riots.

  • June 1960 - Soviet Premier Nikita Khrushchev pledges support for "wars of national liberation" in an address to the United Nations.
  • January 1961 - In his inauguration speech, President Kennedy says, "Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe to assure the survival and success of liberty."
  • April 1961 - Soviet Yuri Gagarin is the first man in space.
    Central Intelligence Agency-backed invasion of Cuba at the Bay of Pigs fails.
  • August 1961 - The Berlin Wall is erected between West and East Berlin.
  • September 1961 - As part of a campaign to reduce the United States' vulnerability to nuclear attack, President Kennedy advises Americans to build fallout shelters. President Kennedy's letter in the September issue of Life
    magazine sets off a wave of "shelter-mania" which lasts for about a year.
  • October 1962 - U.S. reconnaissance discovers Soviet missiles in Cuba. The United States blockades Cuba for 13 days until the Soviet Union agrees to remove its missiles. The United States also agrees to remove its missiles from Turkey.
  • June 1963 - The United States and Soviet Union set up a hotline (teletype) between the White House and the Kremlin.
  • August 1963 - The United States and Soviet Union sign the Limited Test Ban Treaty, which prohibits underwater, atmospheric, and outer space nuclear tests. More than 100 countries have ratified the treaty since 1963.
  • March 1965 - First U.S. combat troops are sent to Vietnam.
  • 1966-1967 - The large number of utility orders for nuclear power reactors makes nuclear power a commercial reality in the United States.
  • July 1968 - Nuclear Nonproliferation Treaty (NPT)--calling for halting the spread of nuclear weapons capabilities--is signed. By 1970, more than 50 countries had ratified the NPT. By 1986, more than 130 countries had ratified it.
  • July 1969 - American Neil Armstrong is the first man on the moon.

The 1970s

On June 17, 1972, five men employed by the Committee to Re-elect the President (later known as CREEP) were arrested while breaking into the Democratic National Headquarters at the Watergate Hotel to plant listening devices in the phones and steal campaign strategy documents. Two former White House aides working for CREEP, G. Gordon Liddy and E. Howard Hunt, were also arrested. Liddy was a former Federal Bureau of Investigation (FBI) agent, and Hunt was the Central Intelligence Agency agent responsible for planning the Bay of Pigs invasion in 1961. The seven Watergate burglars were indicted on September 15, 1972. In November 1972, President Richard Nixon defeated George McGovern in a landslide.

In February 1973, the U.S. Senate established the Select Committee on Presidential Campaign Activities to investigate the Watergate break-in and rumors of other campaign irregularities. Over the next few months, the conspiracy to cover-up White House involvement in the break-in began to unravel. The acting Director of the FBI resigned after admitting he destroyed evidence on the advice of White House aides. White House Chief of Staff H.R. Haldeman, White House Domestic Affairs Assistant John Ehrlichman, and presidential counsel John Dean, resigned on April 30, 1973. Haldeman, Ehrlichman, and two others were later convicted of obstructing the investigation of the break-in. During a televised speech, President Nixon denied any knowledge of the cover-up. However, John Dean testified before the Senate committee that Nixon authorized "hush money" to the burglars. White House aide Alexander Butterfield also testified that Nixon taped every conversation in the Oval Office.

This revelation touched a battle of wills between the Senate Committee and the President over releasing the tapes. In October 1973, Nixon ordered the Attorney General to fire Special Prosecutor Archibald Cox because Cox refused to accept Nixon's offer to release a "synopsis" of the tapes. The Attorney General and his assistant refused to follow the order and resigned. The House of Representatives began to consider impeaching the President on October 23. Nixon turned over the tapes, but two proved to be missing and one had a 18 1/2 minute gap in it. In January 1974, Nixon refused to surrender over 500 tapes and documents subpoenaed by the Senate. On July 24, the Supreme Court unanimously ruled that Nixon must turn over the tapes, which he did eight hours later. By the end of July, the House Judiciary Committee approved articles of impeachment against President Nixon, charging him with obstructing justice, repeatedly violating his oath of office, and unconstitutionally defying Senate subpoenas. On August 5, Nixon revealed the "smoking gun" that tied him to the Watergate cover-up. He released transcripts of a conversation with Haldemon that showed President Nixon ordered the FBI to stop investigating the break-in six days after it occurred. President Nixon resigned on August 8, 1974. President Ford pardoned Nixon a month later.

In addition to breaking and entering and obstruction of justice, the investigation of the Watergate break-in revealed an impressive list of offenses. Illegal campaign contributions to CREEP financed "dirty tricks" to discredit key Democratic leaders. It was also revealed President Nixon had taken illegal tax deductions and used $10 million in government funds to improve his houses in Florida and California. The illegal, secret war against Cambodia was also revealed.

  • January 1970 - The National Environmental Policy Act of 1969 is signed, requiring the Federal government to review the environmental impact of any action--such as construction of a building--that might significantly affect the environment.
  • December 1970 - The U.S. Environmental Protection Agency is formed.
  • 1972 - Computer axial tomography, commonly known as CAT scanning, is introduced. A CAT scan combines many high-definition, cross-sectional x-rays to produce a two-dimensional image of a patient's anatomy.
  • January 1973 - The peace treaty ending the Vietnam War is signed. South Vietnam collapses in 1975 after U.S. troops are withdrawn.
  • March 1974 - The Atomic Energy Commission establishes the Formerly Utilized Sites Remedial Action Program (FUSRAP) to identify former Manhattan Project and AEC sites that are privately owned but need remedial action.
  • October 1974 - The Energy Reorganization Act of 1974 abolishes the Atomic Energy Commission and creates the Energy Research and Development Administration and the Nuclear Regulatory Commission.
  • October 1976 - The Resource Conservation and Recovery Act (RCRA) is passed to protect human health and the environment from the potential hazards of waste disposal.
  • April 1977 - President Carter bans the recycling of used nuclear fuel from commercial reactors.
  • August 1977 - The Voyager 2 spacecraft is launched carrying a 12-inch copper phonograph record containing greetings in every language. The spacecraft's electricity is generated by the decay of plutonium pellets.
  • October 1977 - The U.S. Department of Energy (DOE) replaces the Energy Research and Development Administration and consolidates Federal energy programs and activities.
  • April 1978 - The United States cancels development of the neutron bomb, which would theoretically destroy life but leave buildings intact.
  • November 1978 - The Uranium Mill Tailings Radiation Control Act of 1978 directs DOE to stabilize and control uranium mill tailings at inactive milling sites and vicinity properties. DOE forms the Uranium Mill Tailings Remedial Action (UMTRA) Program as a result.
  • March 1979 - Three Mile Island Nuclear Powerplant near Harrisburg, Pennsylvania suffers a partial core meltdown. Minimal radioactive material is released.
  • June 1979 - The United States and Soviet Union sign the Strategic Arms Limitation Treaty (SALT) II, which limits each side's arsenals and restricts weapons development and modernization.
  • November 1979 - American hostages are taken in Iran.
  • December 1979 - The Soviet Union invades Afghanistan.


The 1980s

Mikhail Gorbachev became the Secretary General (and later President) of the Soviet Union in March 1985, drastically changing the character of Soviet leadership. Gorbachev started a group of domestic policies call glasnost, which means openness in Russian. He began to reform the Soviet economy by introducing elements of a free market system, such as competition, to make it more efficient. Glasnost also loosened the Soviet government's grip on its citizens' private and cultural life. Dissidents, such as Andrei Sacharov, were released.

  • October 1980 - The West Valley Demonstration Project Act of 1980 directs DOE to construct a high-level nuclear waste solidification demonstration at the West Valley Plant in New York. The only commercial nuclear fuel reprocessing plant in the United States, the West Valley Plant recovered uranium and plutonium from spent nuclear fuel from 1966-1972. Nearly 600,000 gallons of high-level nuclear waste are stored at the plant.
  • November 1980 - Single-shell nuclear waste storage tanks at the Hanford Plant in Washington no longer receive waste. The liquid waste is being transferred to newer design double-shell tanks.
  • December 1980 - The Low-Level Radioactive Waste Policy Act is passed, making states responsible for the disposal of their own low-level nuclear waste, such as from hospitals and industry.

    The Comprehensive Environmental Response, Compensation, and Liability Act (also known as Superfund) is passed in response to the discovery in the late 1970's of a large number of abandoned, leaking hazardous waste dumps. Under Superfund, the Environmental Protection Agency identifies hazardous sites, takes appropriate action, and sees that the responsible party pays for the cleanup.

  • 1982 - The Shippingport nuclear powerplant, built in 1957, is retired. Congress assigns the decontamination and decommissioning of this commercial reactor to DOE. This is the first complete decontamination and decommissioning of a reactor in the United States. The reactor vessel is shipped to a low-level waste disposal facility at Hanford, Washington. The site is cleaned and released for unrestricted use in November 1989.
  • January 1983 - The Nuclear Waste Policy Act of 1982 is signed, authorizing the development of a high-level nuclear waste repository.
  • March 1983 - Reagan terms the Soviet Union the "evil empire" and announces the Strategic Defense Initiative (Star Wars), a satellite-based defense system that would destroy incoming missiles and warheads in space.
  • November 1983 - DOE begins construction of the Defense Waste Processing Facility (DWPF) at the Savannah River Plant in South Carolina. DWPF will make high-level nuclear waste into a glass-like substance, which will then be shipped to a repository deep within the Earth for permanent disposal.
  • April 1984 - In LEAF (Legal Environmental Assistance Foundation) vs. Hodel, the court rules that DOE's Y-12 Plant in Tennessee is subject to the Resource Conservation and Recovery Act.
  • August 1985 - The Soviet Union announces a nuclear testing moratorium.
  • January 1986 - Soviet President Gorbachev calls for disarmament by the year 2000.
  • April 1986 - Chernobyl Nuclear Reactor meltdown and fire occur in the Soviet Union. Massive quantities of radioactive material are released.
  • March 1987 - Soviet President Gorbachev proposes elimination of European short and medium range missiles. Later, NATO and West Germany support Gorbachev's proposal, with some changes.
  • December 1987 - Soviet President Gorbachev and President Reagan sign the Intermediate-Range Nuclear Forces (NIF) Treaty, the first arms treaty signed by the superpowers calling for elimination of a whole class of weapons--intermediate range missiles.

    Nuclear Waste Policy Amendments Act designates Yucca Mountain, Nevada, for scientific investigation as candidate site for the nation's first geological repository for high-level radioactive waste and spent nuclear fuel.

  • November 1989 - DOE changes its focus from nuclear materials production to one of environmental cleanup, openness to public input and overall accountability by forming the Office of Environmental Restoration and Waste Management.

    The Berlin Wall is torn down. Many communist governments in Eastern Europe collapse.

  • 1989 - Nuclear weapons production facilities at Rocky Flats Plant in Colorado and Fernald Feed Materials Production Center in Ohio cease production and change their missions to cleaning up their facilities.