- 1794 – The United States Government establishes a permanent navy and authorizes the building of six frigates.
- 1851 – First reported sighting of the Yosemite Valley by Europeans.
- 1915 – Typhoid Mary, the first healthy carrier of disease ever identified in the United States, is put in quarantine, where she would remain for the rest of her life.
- 1980 – Silver Thursday: A steep fall in silver prices, resulting from the Hunt Brothers attempting to corner the market in silver, led to panic on commodity and futures exchanges.
- 1998 – The Food and Drug Administration approves Viagra for use as a treatment for male impotence, the first pill to be approved for this condition in the United States.