The first U.S. patent was granted to Samuel Hopkins for a process of making potash on July 31, 1790.
Notes on verification
Confirmed by USPTO, National Archives, and Smithsonian; consistent historical record with primary document evidence (patent signed by Washington, countersigned by Jefferson and Randolph). [tier=silver indep_score=1.0 clusters=2 claim_tier=notable | framework convergence=partial on U.S. government patent records from 1790 (upstreams: U.S. Patent and Trademark Office historical records, National Archives) — publishers independent, evidence may not be | kind=empirical eligibility=high]
Sources
- Milestones in U.S. patenting | USPTO (seed:firsts_and_inventions)
- https://www.archives.gov/publications/prologue/2001/spring/patent-act.html (corroboration)
- https://www.si.edu/spotlight/first-patent (corroboration)