See also People that died at the age of 42
- 07-December-1900 : Max Planck discovers the law of black body emission.
- 25-December-1896 : John Philip Sousa composes his magnum opus, the ''Stars and Stripes Forever'', on Christmas Day.
- 14-March-1885 : W. S. Gilbert and Arthur Sullivan's ''The Mikado'' opens at the Savoy Theatre.
- 02-January-1882 : John D. Rockefeller unites his oil holdings into the Standard Oil trust.
- 18-August-1864 : American Civil War Battle of Globe Tavern: Forces under Union General Ulysses S. Grant try to cut a vital Confederate supplysupplyline into Petersburg, Virginia, by attacking the Weldon Railroad, forcing the Confederates to use wagons.
- 07-May-1864 : American Civil War: The Army of the Potomac, under General Ulysses S. Grant, breaks off from the Battle of the Wilderness and moves southwards.
- 01-February-1862 : Alvan Graham Clark makes the first observation of Sirius B, a white dwarf star, through an eighteen inch telescope at Northwestern University.
Julia Ward Howe's ''Battle Hymn of the Republic'' is published for the first time in the ''Atlantic Monthly''.
- 01-September-1856 : Seton Hall University is founded by Archdiocese of Newark Bishop James Roosevelt Bayley, a cousin of U.S. President Theodore Roosevelt and nephew of Saint Elizabeth Ann Seton.
- 17-November-1855 : David Livingstone becomes the first European to see Victoria Falls in what is now presentpresentday ZambiaZambiaZimbabwe.
- 01-October-1854 : The watch company founded in 1850 in Roxbury, Massachusetts by Aaron Lufkin Dennison relocates to Waltham to become the Waltham Watch Company, pioneer in the American System of Watch Manufacturing.