Koch establishes the germ theory
December 1850
Koch and Pastuer develop Germ Theory
Using several experiments Koch and Pasteur develop the theory that explains spread of disease and severity.
Los Angeles and San Francisco are incorportaed
Two new cities along the western apart of the United States sprout. The next New York?
California reaches statehood
The newest state is added to the union as the 31st state.
Great famine still attacks Ireland
Ireland is struck by a huge potato famine.