March 14, 1794

Eli Whitney

Eli Whitney receives a U.S. patent for his cotton gin

The famous number 72X did not exist in 1794. Patent officials assigned it decades later, after a fire destroyed the original records.

14 March 1794: the grant

The United States granted Eli Whitney a patent for his cotton-cleaning machine on 14 March 1794. It covered his improvement for separating the seeds of short-staple cotton by means of a toothed cylinder, a slotted breastwork and a clearer mechanism.

President George Washington was a signatory to the early federal letters patent, and Secretary of State Edmund Randolph countersigned it under the Patent Act of 1793.

Paper that arrived after the machines

The grant followed Whitney's petition of 20 June 1793 and the detailed description and oath he had notarised on 28 October. The term ran 14 years, stated as running from 6 November 1793.

It also arrived late. By the grant date, unauthorised versions of the mechanically simple gin were already operating, and holding a federal exclusive right did not mean Whitney and Miller could practically stop the copying; enforcement under the early patent laws proved prolonged and costly.

What survives, and what was reconstructed

The patent had no serial number when it was granted. The designation 72X was assigned retroactively after the 1836 Patent Office fire.

That fire took the originals with it. The drawing commonly presented as Whitney's is a restoration made in 1845 from descriptions and surviving machines.

Sources

Researched 23 Aug 2026 6 sources 2 audit passes

How this was checked

Researched from the web into a fact sheet, rewritten from that sheet, then audited against it by a different model. How the pipeline works →

What the sources leave uncertain

The grant date is firmly documented.
The familiar patent drawing is a later reconstruction. The original Patent Office records were destroyed in the 1836 fire, and the surviving restored drawing was made in 1845 from descriptions and surviving machines.