Thomas L. Jennings was awarded a patent on March 3, 1821 (US Patent 3306x) for his discovery of a process called dry-scouring which was the forerunner of today's modern dry-cleaning.

Thomas L. Jennings (1791 – February 12, 1856) was an African-American tradesman and abolitionist in New York City, New York. He operated and owned a tailoring business.

Jennings became active in working to better civil rights for the African-American community. In 1831, he was selected as assistant secretary to the First Annual Convention of the People of Color in Philadelphia, Pennsylvania, which met in June of that year. He helped arrange legal defense for his daughter, Elizabeth Jennings, in 1854 when she challenged a private streetcar company's segregation of seating and was arrested. She was defended by the young Chester Arthur, and won her case the next year.

With two other prominent African-American leaders, Jennings organized the Legal Rights Association in 1855 in New York, which raised challenges to discrimination and organized legal defense for court cases. He founded and was a trustee of the Abyssinian Baptist Church, a leader in the African-American community.

Thomas L. Jennings was born free to a free African-American family in New York City. As a youth he learned a trade as a tailor. He built a business and married a woman named Elizabeth, who was born in 1798 in Delaware into slavery and died March 5, 1873. Under New York's gradual abolition law of 1799, she was converted to the status of an indentured servant and was not eligible for full emancipation until 1827. Children born to enslaved mothers before 1827 were considered to be born free, but were required to serve apprenticeships to the mothers' masters until they reached their mid- to late 20s.

He and his wife had three children: Matilda Jennings (b. 1824, d. 1886), Elizabeth Jennings (b. March 1827 d. June 5, 1901), and James E. Jennings (b. 1832). Matilda Jennings was a dressmaker and wife of James A. Thompson, a Mason. Elizabeth Jennings was the wife of Charles Graham, whom she married on June 18, 1860. James E. Jennings was a public school teacher.

Jennings built a business as a tailor, and was well-respected in the community. He spent his early earnings on legal fees to purchase his wife and some of their children out of slavery. Their daughter Elizabeth Jennings was born free in March 1827 and became a schoolteacher and church organist.

Jennings also supported the abolitionist movement and became active in working for civil rights of free African-Americans. He was active on issues related to emigration to other countries; opposing colonization in Africa, as proposed by the American Colonization Society; and supporting expansion of suffrage for African-American men.

Thomas Jennings was the first African American to receive a patent, on March 3, 1821. His patent was for a dry-cleaning process called “dry scouring”. ... Thomas L. Jennings Dry Scouring technique created modern day dry cleaning

Jennings was a leader in the cause of abolitionism and African-American civil rights. After his daughter, Elizabeth Jennings March 1827-June 5, 1901, was forcibly removed from a "whites only" streetcar in New York City, he organized a movement against racial segregation in public transit in the city; the services were provided by private companies. Elizabeth Jennings won her case in 1855. Along with James McCune Smith and Rev. James W.C. Pennington, her father created the Legal Rights Association in 1855, a pioneering minority-rights organization. Its members organized additional challenges to discrimination and segregation, and gained legal representation to take cases to court. A decade after Elizabeth Jennings won her case, New York City streetcar companies stopped practicing segregation.