1842 was a common year starting on Saturday (see link for calendar).

Events

• February 21 - John J. Greenough patents the sewing machine.
• March 5 - 00 Mexican troops led by Rafael Vasquez invade Texas briefly occupy San Antonio and then head back to the Rio Grande. This is the first such invasion since the Texas Revolution.
• March 30 - Anesthesia is used for the first time in an operation (Dr. Crawford Long performed the operation and ether was used).
• March 31 - Middleton Junction and Oldham Branch Railway line opened up to Werneth in North West England.
• August 9 - Webster-Ashburton Treaty is signed, establishing the United States-Canada border east of the Rocky Mountains.
• Massacre of Elphinstone's British army on the road from Kabul to Jallalabad, Afghanistan, by Mohammed Akbar , son of Dost Mohammed Khan
• August 29 - Treaty of Nanking signing ends the First Opium War
• British Empire annexes Hong Kong
• Pentonville Prison built.
• New Zealand seat of government moves from Russell to Auckland
• Ohio's Wesleyan University is established.

Births

• February 3 - Sidney Lanier, American writer (d. 1881)
• February 4 - Arrigo Boito, Italian poet and composer (d. 1918)
• February 25 - Karl May, German writer (d. 1912)
• March 10 - Mykola Lysenko, composer
• March 18 - Stéphane Mallarmé, French poet (d. 1898)
• April 14 - Catherine Eddowes, fourth confirmed victim of Jack the Ripper (d. 1888)
• May 8 - Emil Christian Hansen, fermentation physiologist
• May 13 - Arthur Sullivan, English composer (d. 1900)
• May 17 - August Thyssen , Swiss industrialist (d. 1926)
• August 23 - Osborne Reynolds, engineer and physicist
• September 13 - John H. Bankhead, United States Senator (d. 1920)
• September 21 - Abd-ul-Hamid II, Ottoman sultan
• October 14 - Joe Start, baseball player
• December 9 - Peter Kropotkin, Russian anarchist (d. 1921)
• Anna Elizabeth Dickenson, orator
• Rikard Nordraak, Norwegian composer

Deaths

• January 19 - Comte Siméon Joseph Jérôme , French jurist and politician.
• March 6 - Constanze Mozart , wife of Wolfgang Mozart
• March 13 - Henry Shrapnel, soldier, inventor
• March 23 - Stendhal, French writer (b. 1783)
• March 30 - Elisabeth Vigee-Lebrun, French painter
• April 4 - Jean Moufot, French philosopher and mathematician
• May 8 - Jules Dumont d'Urville, explorer
• July 28 - Clemens Brentano, German poet (b. 1778)
• September 15 - Francisco Morazán, President of Central America