Unexpectedly Intriguing!
05 February 2021

This edition of Inventions in Everything starts with a simple question: "Who was the first African-American inventor to earn a U.S. patent for their invention?"

The answer is Thomas L. Jennings, a free-born resident of New York City who invented "dry scouring", a precursor to modern dry cleaning, which was the subject of the 3,306th patent issued by the United States government on 3 March 1821.

Unfortunately, we cannot share any information directly from the issued patent because it was among the hundreds of patents that were lost in the 15 December 1836 fire at the U.S. Patent Office. To find out more Jennings and his patented invention, we turned to the modern dry cleaning industry, which recognizes Jennings' great contribution to their trade and has put together some of the story behind his invention.

Jennings became a tailor in New York City in the 1820s, then went on to start a clothing shop. While running that business, the 29-year-old Jennings developed dry scouring, a method of removing dirt and grease from delicate clothing.

According to National Clothesline magazine, many of Jennings’ customers at the clothing shop were upset when their garments became dirty. But because of the natural materials used to make them, the garments couldn’t be washed the old-fashioned way; doing so would cause them to shrink. As a result, people either continued wearing the dirty clothes or simply tossed them out, the magazine says.

“While Jennings would have profited from making and selling new clothes to replace the soiled items, he also hated to see the garments, which he had worked hard to create, cast aside,” National Clothesline says. “He set out experimenting with different solutions and cleaning agents, testing them on various fabrics, until he found the right combination to effectively treat and clean them, thus coming up with the method that led to his patent for ‘dry scouring.’”

We've had to emphasize that Jennings was a free-born man because that status played an important role in the U.S. Patent Office's issuance of a patent for the invention. The Intellectual Property Owners Education Foundation explains why that mattered:

The patent to Jennings generated considerable controversy during this period. Slaves at this time could not patent their own inventions. This regulation dated back to the U.S. patent laws of 1793. The regulation was based on the legal presumption that “the master is the owner of the fruits of the labor of the slave both manual and intellectual.” Thomas Jennings, however, was born a free man and thus was able to gain exclusive rights to his invention and profit from it.

And profit from it he did, including using his patent letter to win a court case against a competing tailor:

When a rival tailor illegally used the invention, he found Jennings was not one to trifle with. Jennings sued him in the city’s Marine Court and won $50 when he dramatically produced the Letters of Patent.

The patent letter however carried more than financial value to Thomas Jennings, to which Frederick Douglas called attention in his 1859 eulogy marking Jennings' passing:

In his boyhood, Mr. Jennings served an apprenticeship with one of the most celebrated of the New York tailors. Soon after reaching manhood, he entered business on his own account, and invented a method of renovating garments, for which he obtained letters patent from the United States. Although it was well known that he was a black man of 'African descent,' these letters recognize him as a 'citizen of the United States.' This document, in an antique gilded frame, hangs above the bed in which Mr. Jennings breathed his last, and is signed by the historic names of John Quincy Adams and William Wirt, and bears the broad seal of the United States of America.

U.S. Patent 3,606 remains lost however. The U.S. patent laws of 1790 help explain why, although for reasons not having anything to do with his status as a black man of African descent. Here, after its 1836 fire, the U.S. Patent Office sought to reconstruct its records with inventors asked to resubmit copies of their drawings and other information to the Patent Office. The inventors of 2,845 patents did, allowing their patent records to be restored. The U.S. Patent Office indicates these restored patents with an "X", which are commonly known as "X-patents".

But unlike many of these inventors, Jennings would have had little financial incentive to re-create the records of his patent. Under the 1790 patent law, the term of U.S. patents was set to expire 14 years after their date of issuance. Jennings' U.S. Patent 3,306 was issued on 3 March 1821 and therefore expired on 3 March 1835, some 21 months before the patent office fire.

A similar story can be told for the vast majority of patents issued in the years before the fire. From 1790 to 1836, the U.S. Patent Office issued some 10,132 patents. Of these patents, 3,700 were issued in the years from 1790 through 1822, which covers nearly all the patents that would have expired by the time of the Patent Office fire. Among these patents, just 328 were restored as X-patents.

For Jennings, the success of his patent allowed him to use the profits from his invention to purchase the freedom of enslaved family members and to support the growing abolition movement to permanently end the institution of slavery in the United States. His role in that movement is what connected him with Frederick Douglass, who also described him as "one of the bold men of color" in his eulogy for his contributions to it.

Which do you suppose is the greater creative achievement for the man who invented dry cleaning?


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