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Letter to FDR
Albert Einstein wrote Franklin D. Roosevelt about the dangerous development of Uranium that could lead to chain reactions and powerful bombs. In October, Roosevelt develops a committee to study the development of Uranium.
http://www.atomicarchive.com/History/mp/chronology.shtml
http://upload.wikimedia.org/wikipedia/commons/d/d3/Albert_Einstein_Head.jpg -
Development of Uranium Research
John R. Dunning and colleagues discover that fission is much more successful in the rare U-235 rather than the abundant U-238
http://www.atomicarchive.com/History/mp/chronology.shtml
http://www.earthtimes.org/newsimage/uranium-mining-power-weapons_20312.jpg -
Pearl Harbor
The Japanese bomb Pearl Harbor. dragging the United States into WWII. Three days later, Italy and Germany declare war on the United States.
http://www.atomicarchive.com/History/mp/chronology.shtml
https://www.pearlharboroahu.com/images/Attack-pearl-harbor.jpg -
Approving the Atomic Bomb
Roosevelt approves the plan, proposed by Vannevar Bush, to build an atomic bomb.
http://wmbf.images.worldnow.com/images/18874569_BG1.jpg
http://www.atomicarchive.com/History/mp/chronology.shtml -
Manhattan Project Established
The Manahattan Engineer District is established in New York City, starting the Manhattan Project.
http://nuclearweaponarchive.org/Usa/Med/Szilein.jpg
http://www.atomicarchive.com/History/mp/chronology.shtml -
More Fissionable Material Needed
J. Roppert Oppenheimer decides that more fissionable material is needed to make a successful atomic bomb.
http://upload.wikimedia.org/wikipedia/commons/0/03/JROppenheimer-LosAlamos.jpg
http://www.atomicarchive.com/History/mp/chronology.shtml -
Bomb in the Making
The Military Policy Committee decides to go directly from the research stage to industrial-scale production, while also deciding not to build a centrifuge plant.
http://www.atomicarchive.com/History/mp/Images/SB57.jpg
http://www.atomicarchive.com/History/mp/chronology.shtml -
Hanford Washington
Hanford Washington is selected as a plutonium production facility. Three Reactors, B, D, and F are built.
http://www.atomicarchive.com/History/mp/chronology.shtml
http://www.atomicarchive.com/History/sites/Images/B_reactor.jpg -
3x more fissionable material
It is realized that three times more fissionable material is needed for a successful atomic bomb than at first thought.
http://www.atomicarchive.com/History/mp/chronology.shtml -
Test Dropping
Little Dummy Test Bombs called "Pumpkins" are dropped by Paul Tibbet's 393rd Bombardment Squad.
http://upload.wikimedia.org/wikipedia/commons/1/17/Pumpkin_bomb.jpg
http://www.atomicarchive.com/History/mp/chronology.shtml -
Manhattan Plan Probable
The Manhattan Plan is changed from doubtful to probable as Hanford and Oak ridge produce more fissionable material and Los Alamos, New Mexico makes advances in chemistry
http://www.atomicarchive.com/History/mp/chronology.shtml
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FDR dies
Franklin D. Roosevelt dies and Truman is quickly informed about the nuclear plan, but is told to keep it secret.
http://www.atomicarchive.com/History/mp/chronology.shtml
http://en.wikipedia.org/wiki/File:FDR_in_1933.jpg -
Plan turned down
The idea for demonstrating the atomic bomb before it is detonated in combat is shot down by the Interim Committee
http://www.atomicarchive.com/History/mp/chronology.shtml -
Atomic Bomb Tested in Mexico
The United States detonates its first atomic bomb near Alamogordo, New Mexico. The bomb explodes with a force eqivalent to 18,000 tons of TNT.
http://www.pbs.org/wgbh/amex/bomb/timeline/index.html?utm_source=Facebook&utm_medium=pbsofficial&utm_campaign=thisdayhistory
http://www.trumanlibrary.org/photographs/72-4148.jpg -
Japanese Reject Potsdam Proclamation
The Japanese refuse to surrender, even when the United States has warned Stalin about their new dangerous weapon.
http://withfriendship.com/images/h/36859/the-potsdam-declaration-called.jpg
http://www.atomicarchive.com/History/mp/chronology.shtml -
The "Little Boy" Bomb is dropped on Hiroshima
The "Little Boy" atomic bomb was dropped 1,900 feet above Hiroshima, killing 140,000 people with 12.500 tons of TNT.
http://www.pbs.org/wgbh/amex/bomb/timeline/index.html?utm_source=Facebook&utm_medium=pbsofficial&utm_campaign=thisdayhistory' >American Experience</a>
http://www.english.illinois.edu/maps/poets/g_l/levine/bombing.htm -
The "Fat Man" bomb is dropped on Nagaski
The "Fat Man" atomic bomb is dropped 1,900 feet above Nagaski, killing 70,000 with 22,000 pounds of TNT.
http://www.pbs.org/wgbh/amex/bomb/timeline/index.html?utm_source=Facebook&utm_medium=pbsofficial&utm_campaign=thisdayhistory
http://epathram.com/pacha/files/2010/08/nagasaki-fat-man-plutonium-bomb-explosion-epathram.jpg -
Japan Surrenders
Japan formally surrenders, ending a threat to the United States.
http://americanhistory.about.com/library/timelines/bltimelinemanhat.htm -
End of the Manhattan Plan
All atomic energy activities are moved from the Manhattan Engineer District to the United States Atomic Energy Commission, ending the Manhattan Plan.
http://www.atomicarchive.com/History/mp/chronology.shtml -
Atomic Ban Treaty
The Limited Nuclear Test Ban Treaty goes into effect, limiting use of nuclear weapons
http://www.pbs.org/wgbh/amex/bomb/timeline/index.html?utm_source=Facebook&utm_medium=pbsofficial&utm_campaign=thisdayhistory
http://www.jfklibrary.org/~/media/assets/Education and Public Programs/Education/For Teachers Manual Upload/JFKSignsTestBanTreaty.jpg
