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.
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