1763

British soldiers, besieged by American Indian tribes during Pontiac's Rebellion, give blankets infected with the smallpox virus to tribal representatives.

1892

June 25: Shiro Ishii is born near Tokyo.

1904

Fildes enters medical school to study to become a surgeon, but soon transfers to bacteriology.

1920

Ishii receives his medical degree from Kyoto Imperial University; he soon develops an interest in bacteriology.

1928

Spurred by his interest in biological weapons, Ishii begins a two-year fact-finding trip around the world, visiting Europe and America.

1931

Fildes edits a nine-volume treatise on bacteriology that is published by the Medical Research Council, whose Bacteriological Chemistry Unit he heads.

1933

March: U.S. Army Medical Corps Major Leon Fox publishes an article in the magazine Military Surgeon dismissing the idea of biological weapons. "Practically insurmountable difficulties prevent the use of biologic agents as effective weapons," Fox writes.

1937

Construction commences on a large Japanese biological weapons complex called Ping Fan near the Manchurian city of Harbin.

1940

The Japanese biological weapons complex Ping Fan begins operations. It employs some 3,000 personnel under Ishii's direction, working on a wide variety of biological agents, including bacteria that cause plague and anthrax. Over the next five years, Unit 731, as it becomes known, conducts horrific tests on Chinese prisoners and, allegedly, some Allied POWs. Victims are injected with, forced to eat, and made to breathe deadly pathogens. Often prisoners are killed before the diseases have become terminal so autopsies can be performed. Ishii's men also create bacteriological bombs, and later that year Japanese warplanes repeatedly drop porcelain bombs containing fleas infected with plague over Chinese towns, resulting in several outbreaks of plague among the human population.

Meanwhile, in England, a new biology department is established at Porton Down with Fildes as its head. His initial research focuses on botulism and anthrax.

1942

January 2: Churchill's Defense Committee meets and gives the go-ahead for production of these cattle cakes. Later that year the first of some five million cattle cakes are manufactured at Porton Down. The plan, named, "Operation Vegetarian," is to drop them from aircraft over Germany in the hope of wiping out its cattle. But it is never implemented.

February 17: Stimson's committee issues the first of its two reports, concluding that biological warfare is "distinctly feasible" and the United States should begin its own biological weapons program immediately.

April 29: Stimson writes to President Franklin Roosevelt conceding that biological warfare is "a dirty business" but arguing America must be prepared. In May Roosevelt approves the creation of a U.S. biological weapons program.

May 27: British-trained commandoes ambush high-ranking Nazi leader Reinhard Heydrich near Prague. Although he suffers only minor wounds, Heydrich will die suddenly a week later. Fildes later claims to have "had a hand" in the assassination, perhaps by supplying the commandoes with grenades contaminated with botulinum toxin.

June-July: The Japanese test Salmonella on Chinese prisoners. Then they disperse the bacteria that cause typhoid, cholera, and other food-borne diseases over Chinese populations.

July 15: A team of Porton Down scientists led by Fildes begin outdoor testing of anthrax bacteria on the remote Scottish island of Gruinard. They set off anthrax-filled bombs and observe their impact on a group of sheep placed downwind. Within a few days, most of the sheep die.

September 26: Fildes' team has an anthrax bacteria bomb dropped from an airplane onto Gruinard. Although it lodges in a bog and does not infect any sheep, a similar test is more successfully repeated a month later on a beach in Wales.

November: Fildes arrives in Washington to meet with officials there. Recognizing U.S. superiority in mass production, he asks for American help in making biological weapons. Fildes' first request is for seven pounds of botulinum toxin (code named "Agent X"), which is a proteinaceous substance produced by the bacterium Clostridium botulinum. Later that month, Ira Baldwin, now a professor and head of the bacteriology department at the University of Wisconsin, receives a call from Colonel William Kabrich of the U.S. Army Chemical Warfare Service. Kabrich asks Baldwin to attend a meeting at the National Academy of Sciences in Washington. Once there, Baldwin and other scientists are sworn to secrecy and then asked whether they believe that the U.S. can produce mass quantities of biological agents. Baldwin says yes, and 10 days later Kabrich asks him to head up the program.

December 21: Baldwin arrives in Maryland and becomes scientific director and administrator of the U.S. Army's biological warfare research program. He soon begins recruiting colleagues from University of Wisconsin to join him.

1944

March 8: Convinced that the Germans will use biological weapons if able to produce them and that the British must be able to retaliate in kind, Churchill places order for 500,000 "anthrax" bombs, i.e., bombs containing anthrax bacterial spores, with the Americans.

May: Camp Detrick produces a first batch of 5,000 anthrax bombs for the British, but it is clear that filling the whole order (plus another 500,000 bombs for American use) exceeds its capacities. The Americans decide to construct a new production facility near Vigo, Indiana, and begin safety testing there that summer.