The history of United States patent law started even before the U.S. Constitution was adopted, with some state-specific patent laws. The history spans over more than three centuries.
The first U.S. patent, issued to Samuel Hopkins on July 31, 1790, for an innovative way of making "pot ash and pearl ash"
Hotchkiss v. Greenwood
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Hotchkiss v. Greenwood, 52 U.S. 248, was a United States Supreme Court decision credited with introducing into United States patent law the concept of non-obviousness as a patentability requirement, a
The patented doorknob – from U.S. Pat. No. 2197
Justice John McLean – 1849
Justice Samuel Nelson
Justice Levi Woodbury