- Jan 2 Roger Weightman Hanson, American Brigadier General (Confederate Army), dies in Battle of Murfreesboro at 35
- Jan 9 Ferdinand Huber, Swiss composer, dies at 71
- Jan 10 Lyman Beecher, US Presbyterian clergyman, temperance movement leader (b. 1775)
- Jan 15 David Rumph Jones, American Major General (Confederate Army), dies at 37
- Jan 17 Horace Vernet, French painter of battles and Orientalist subjects, dies at 73
- Mar 11 Sir James Outram, 1st Baronet, English general (b. 1803)
- Mar 17 John Pelham, U.S. Confederate artillery major, dies in battle at 24
- Mar 21 Edwin Vose Sumner, US Union-general-major (Fair Oaks), dies at 66
- Mar 28 James Cooper, US attorney/senator/Union-brigadier general, dies at 52
- Apr 4 Ludwig Emil Grimm, German painter and engraver, dies at 73
- Apr 8 Joseph Netherclift, English composer, dies at 70
- Apr 10 Giovanni B Amia, Italian astronomer/physicist/botanist, dies at 77
- Apr 15 Jan Nepomuk Kanka, Czech composer, dies at 90
- Apr 17 Daniel Smith Donelson, Confederate general and cousin of Andrew Jackson, dies at 61
- Apr 18 Job Plimpton, American composer and organ builder, dies at 79
- May 1 Edward D. Tracy, American Brigadier General (Confederate Army), dies in battle at 29
Stonewall Jackson (1824-1863)
May 10 Confederate general during the American Civil War, dies of pneumonia at 39
- May 14 Emile Prudent, French pianist and composer, dies at 46
- May 16 Lloyd Tilghman, Confederate brigadier general, dies in battle at 47
- May 27 Edward Payson Chapin, American lawyer and Union Army Colonel (posthumously elevated to Brigadier General), dies of injuries from the Siege of Port Hudson, Louisiana at 31
- May 28 Edmund Kirby Jr, American Brigadier General (Union Army), dies of injuries at 23
- Jun 7 Franz Xaver Gruber, Austrian organist and composer (Silent Night), dies at 75
- Jun 9 Benjamin Franklin "Grimes" Davis, Union major, dies in battle at 30
- Jun 17 Isham W Garrott, American attorney and Confederate brigadier general, dies in battle
- Jun 26 Andrew Hull Foote, American Rear Admiral (Union Navy), dies at 56
- Jun 27 Martin E Green, Confederate brigadier general, shot dead at 38
- Jul 1 John Fulton Reynolds, American Union general-major, dies in the Battle of Gettysburg at 42
- Jul 2 Stephen Hinsdale Weed, US Union brigadier general, dies in battle at 28
- Jul 3 Alonzo Cushing, American Union officer, dies at the Battle of Gettsburg at about 22
- Jul 3 Elon John Farnsworth, American Brigadier General (Union Army), dies at the battle of Gettysburg at 25
- Jul 3 George Hull Ward, American general and Union officer in the American Civil War, dies of his wounds at the Battle of Gettysburg at 37
- Jul 3 Little Crow [Ta-oya-te-duta], Mdewakanton Dakota leader (Treaty of Mendota), shot and killed by settlers at about 53
- Jul 3 Richard B. Garnett, American Confederate Brigadier General, killed during Pickett's Charge, Battle of Gettysburg at 45
- Jul 3 Samuel K. Zook, American Union general-major, dies of his wounds from the Battle of Gettysburg at 40
- Jul 3 William Barksdale, American Confederate Brigadier General, dies in the Battle of Gettysburg while leading his brigade's attack at 41
- Jul 4 Paul Joseph Revere, American grandson of Paul Revere, Brigadier General (Union Army), dies at 30
- Jul 5 Lewis Armistead, Confederate brigadier general at Gettysburg (Pickett's Charge), dies of his injuries from the battle of Gettysburg at 46
- Jul 6 Strong Vincent, American army officer (fought at Battle of Gettysburg), dies at 26 fighting at the Little Round Top in Gettysburg
- Jul 8 Francis Kenrick, Irish-American Archbishop of Baltimore (1851-63), dies at 65
- Jul 10 Clement Clarke Moore, American Professor and writer ('Twas the Night Before Xmas), dies at 83
- Jul 10 Paul Jones Semmes, American businessman and Brigadier General (Confederate Army), dies at 48
- Jul 13 John S. Bowen, American Major General (Confederate Army), dies at 32
- Jul 17 J. Johnston Pettigrew, American lawyer and Confederate General in the American Civil War, dies at 35
- Jul 18 William Dorsey Pender, US Confederate Major General, dies of injuries at 29
- Jul 22 Karl Schuberth, German cellist, and composer, dies at 52
Sam Houston (1793-1863)
Jul 26 1st President of Republic of Texas (1836-38, 1841-44) who helped bring Texas into the United States as a constituent state, dies at 70
- Jul 27 William Lowndes Yancey, American Confederate leader (b. 1813)
- Jul 28 James Deshler, US Confederate brigadier general, dies in battle at 30
- Jul 29 Edward Needle Kirk, US Union brigadier general, dies in battle at about 35
- Jul 30 George Crockett Strong, US Union gen-mjr, dies of injuries at 29
- Aug 5 Adolf Friedrich Hesse, German composer, dies at 53
- Aug 8 Angus MacAskill known as 'Giant MacAskill', circus performer (b.1825)
- Aug 13 Eugène Delacroix, French painter and etcher (Journal), dies at 65
- Aug 14 Colin Campbell, British officer (Cawnpore), dies at 70
- Aug 18 Thomas Welsh, US Union brigadier general (Antietam), dies at 39
- Aug 26 John Bz. Floyd, American Governor (Virginia), Secretary of War (1857-60) and Confederate general, dies of failing health at 57
- Sep 6 Lucius March Walker, Confederate brigadier general, dies of his wounds in a duel at 33
- Sep 17 Albartus Telting, Frisian poet (Frisianch Jierboeckjen), dies at 59
- Sep 17 Alfred Victor, Comte de Vigny, French musketeer and writer (Moise, Chatterton), dies at 66
- Sep 19 Preston Smith, American Brigadier General (Confederate Army), dies in battle at 39
- Sep 20 Benjamin Hardin Helm, American attorney and Confederate brigadier general and Abraham Lincoln's brother-in-law, dies at the Battle of Chickamauga at 33
Jacob Grimm (1785-1863)
Sep 20 German philologist, folklorist and editor of "Grimm's Fairy Tales", dies at 78
- Sep 20 William Haines Lytle, American politician, poet and Brigadier General (Union Army), killed in action during the American Civil War at 36
- Oct 2 Justinus van de Brugghen, lawyer/minister of Justice, dies
- Oct 4 Gerrit Schimmelpenninck, Dutch politician (1st Dutch PM as Chairman of the Council of Ministers 1848), dies at 69
- Oct 31 Louis Ludwig Blenker, German/US brigadier general (Union), dies at 51
- Nov 2 Theodore Judah, American civil engineer (1st transcontinental railroad), dies of yellow fever at 37
- Nov 13 Carnot Posey, Confederate brig-general, dies after being wounded in the Battle of Bristoe Station at 45
- Nov 15 Frederik VII, 1st constitutional king of Denmark (1848-63), dies at 55
- Nov 20 James Bruce, 8th Earl of Elgin & Kincardine and Governor (Jamaica), dies at 52
- Nov 21 Joseph Mayseder, Austrian violinist and composer, dies at 74
- Nov 24 Claudius Charles Wilson, American Brigadier General (Confederate Army), dies of fever at camp in Ringgold, Georgia at 32
- Dec 2 Jane Appleton Pierce, American 1st lady (1853-57) and wife of Franklin Pierce, dies of tuberculosis at 57
- Dec 13 Friedrich Hebbel, German poet and dramatist (Maria Magdalena), dies at 50
- Dec 22 Michael Corcoran, Union brigadier general, dies at 36
- Dec 24 William Makepeace Thackeray, British novelist (Vanity Fair), dies at 52