|Covid-19|January 1 – The United Kingdom annexes Lagos Island in modern-day Nigeria.
January 6 – French, Spanish, and British forces arrive in Veracruz, Mexico, beginning the French intervention in Mexico.
January 10 – John Gately Downey, 7th Governor of California, is succeeded by Amasa Leland Stanford.
January 30 – American Civil War: The first US ironclad warship, the USS Monitor, is launched.
January 31 – Alvan Graham Clark makes the first observation of Sirius B, a white dwarf star, through an eighteen-inch telescope at Northwestern University.
February 1 – American Civil War: Julia Ward Howe's "Battle Hymn of the Republic" is published for the first time in the Atlantic Monthly.
February 2 – First railway opens in New Zealand, by Dun Mountain Copper Mining Company.
February 6 – American Civil War: General Ulysses S. Grant gives the United States its first victory of the war, by capturing Fort Henry, Tennessee.
February 11–16 – American Civil War: Battle of Fort Donelson: General Ulysses S. Grant attacks Fort Donelson, Tennessee, capturing it on the last day.
February 20 – Ángel de Saavedra, 3rd Duke of Rivas, named director of Spain's Real Academia Española.
February 21 – American Civil War: Battle of Valverde fought near Fort Craig in New Mexico Territory.
February 22 – American Civil War: Jefferson Davis is officially inaugurated in Richmond, Virginia, to a 6-year term as president of the Confederate States of America.
March 7 – American Civil War: The Battle of Pea Ridge: The Confederates are shut out of Missouri.
March 8 – American Civil War: The iron-clad CSS Virginia (formerly USS Merrimack) is launched at Hampton Roads, Virginia; the Battle of Hampton Roads starts the same day.
March 9 – American Civil War: First battle between two ironclad warships, the USS Monitor and the CSS Virginia, begins.
American Civil War: The U.S. federal government forbids all Union army officers from returning fugitive slaves, thus effectively annulling the Fugitive Slave Act of 1850 and setting the stage for the Emancipation Proclamation.
A smallpox epidemic in San Francisco spreads to British Columbia.
March 28 – American Civil War – Battle of Glorieta Pass: In New Mexico, Union forces succeed in stopping the Confederate invasion of New Mexico Territory (the battle began on March 26).
c. March 31 – Publication of Victor Hugo's epic French historical novel Les Misérables begins.
April 1 – The Spanish and the British end their alliance with France in the French intervention in Mexico.
April 5 – American Civil War – Battle of Yorktown: The battle begins when Union forces under General George B. McClellan close in on the Confederate capital Richmond, Virginia.
April 6 – American Civil War: In Tennessee, the Battle of Shiloh begins.
April 7 – American Civil War – Battle of Shiloh: The Union Army under General Ulysses S. Grant defeats the Confederates near Shiloh, Tennessee.
April 12 – American Civil War – Andrew's Raid – Union volunteers steal a Confederate locomotive, setting off the Great Locomotive Chase, famously involving the use of The General steam locomotive, which still exists in the 21st century.
April 13 – Government of Vietnam is forced to cede the territories of Biên Hòa, Gia Định and Định Tường to France.
April 25 – American Civil War – Capture of New Orleans: Forces under Union Admiral David Farragut capture the Confederate city of New Orleans.
April 26 – American Civil War: The besieged Confederate garrison at Fort Macon, North Carolina surrenders.
May 1– November 1 – 1862 International Exhibition held at South Kensington in London; particularly noted for an exhibit from Japan influential in the development of Anglo-Japanese style.
May 2 – The California State Normal School (later San Jose State University) is created by an Act of the California Legislature.
May 5 – French intervention in Mexico – Battle of Puebla: Mexican General Ignacio Zaragoza defeats the French Army; commemorated each year as "Cinco de Mayo" (Spanish: "Fifth of May").
May 11 – American Civil War: The ironclad CSS Virginia is scuttled in the James River northwest of Norfolk, Virginia.
May 15 – U.S. President Abraham Lincoln signs a bill into law creating the U.S. Bureau of Agriculture (later renamed U.S. Department of Agriculture).
May 20 – U.S. President Abraham Lincoln signs the Homestead Act into law.
May 24 – Westminster Bridge is opened in England. This new bridge designed by Thomas Page had replaced the old bridge.
June 1 – American Civil War – Battle of Fair Oaks. Both sides claim victory.
June 4 – American Civil War: Confederate troops evacuate Fort Pillow on the Mississippi River, leaving the way clear for U.S. Army troops to capture Memphis, Tennessee.
June 5 – Treaty of Saigon: Emperor Tự Đức of the Nguyễn dynasty in Vietnam cedes Saigon, Côn Sơn Island and three southern provinces of what is to become known as Cochinchina (Biên Hòa, Gia Định, and Định Tường) to become part of the French colonial empire. Guerilla leader Trương Định refuses to recognise the treaty.
June 6 – American Civil War – Battle of Memphis: U.S. Army troops capture Memphis, Tennessee from the Confederate States
June 8 – American Civil War – Battle of Cross Keys: Confederate troops under General Stonewall Jackson save the Army of Northern Virginia from a U.S. Army attack on the James Peninsula that was led by General George B. McClellan.
June 12 – John Winter Robinson, the Secretary of State of Kansas, is convicted and removed from office as the result of a bond scandal, becoming the first state executive official to be impeached and removed from office in American history.
June 26 – American Civil War – Battle of Mechanicsville: Confederate General Robert E. Lee defeats the troops of General George B. McClellan in the first of the Seven Days Battles.
The Bureau of Internal Revenue, the forerunner of the Internal Revenue Service, is established in the United States.
Princess Alice, the second daughter of Queen Victoria, marries Prince Ludwig of Hesse and by Rhine.
U.S. President Abraham Lincoln signs into law the Pacific Railroad Acts, authorizing construction of the First Transcontinental Railroad.
The Russian State Library is founded as The Library of the Moscow Public Museum.
July 2 – U.S. President Abraham Lincoln signs the Morrill Land-Grant Act into law, creating a system of land-grant colleges to teach agricultural and mechanical sciences across the United States.
July 4 – Charles Dodgson (better known as Lewis Carroll) extemporises the story that becomes Alice's Adventures in Wonderland for the 10-year-old Alice Liddell and her sisters on a rowboat trip on The Isis from Oxford to Godstow.
July 16 – American Civil War: David G. Farragut becomes the first rear admiral in the U.S. Navy
July 18 – First ascent of Dent Blanche, one of the highest summits in the Alps.
July 23 – American Civil War: Henry W. Halleck takes command of the Union Army.
August 5 – American Civil War – Battle of Baton Rouge: Along the Mississippi River near Baton Rouge, Louisiana, Confederate troops drive Union forces back into the city.
August 6 – American Civil War: The Confederate ironclad CSS Arkansas is scuttled on the Mississippi River after suffering damage in a battle with the USS Essex near Baton Rouge, Louisiana.
August 9 – American Civil War – Battle of Cedar Mountain: At Cedar Mountain, Virginia, Confederate General Stonewall Jackson narrowly defeats Union forces under General John Pope.
August 14 – U.S. President Abraham Lincoln meets with a group of prominent African-Americans – the first time an American President has done so. He suggests that Black people should migrate to Africa or to Central America, but this advice is rejected.
August 17 – Dakota War of 1862 begins in Minnesota as Lakota Sioux attack white settlements along the Minnesota River. They are overwhelmed by the U.S. Army six weeks later.
August 19 – Dakota War of 1862: During an uprising in Minnesota, Lakota warriors decide not to attack heavily defended Fort Ridgely and instead turn to the settlement of New Ulm, killing white settlers along the way.
August 21 – The Vienna Stadtpark opens its gates.
August 28–August 30 – American Civil War – Second Battle of Bull Run: Confederate forces inflict a crushing defeat on Union General John Pope.
August 29–August 30 – American Civil War – Battle of Richmond in Kentucky: Confederate forces led by General Edmund Kirby Smith inflict a crushing defeat on Union General William "Bull" Nelson.
September 1 – American Civil War – Battle of Chantilly: Confederate General Robert E. Lee leads his forces in an attack on retreating Union troops in Chantilly, Virginia, driving them away.
September 2 – American Civil War: U.S. President Abraham Lincoln reluctantly restores Union General George B. McClellan to full command after General John Pope's disastrous defeat at the Second Battle of Bull Run.
September 5 – American Civil War: In the Confederacy's first invasion of the North, General Robert E. Lee leads 55,000 men of the Army of Northern Virginia across the Potomac River at White's Ford near Leesburg, Virginia, into Maryland.
September 10 – Francisco Solano López is appointed 2nd President of Paraguay.
September 17 – American Civil War –
Battle of Antietam: Union forces defeat Confederate troops at Sharpsburg, Maryland, in the bloodiest day in U.S. history, with over 22,000 casualties.
American Civil War: The Allegheny Arsenal explosion results in the single largest civilian disaster during the war.
September 19 – American Civil War – Battle of Iuka: Union troops under Major General William Rosecrans defeat a Confederate force commanded by Major General Sterling Price at Iuka, Mississippi.
Otto von Bismarck becomes prime minister of Prussia following refusal by the country's Landtag to accept the military budget.
American Civil War: Preliminary announcement of the Emancipation Proclamation by U.S. President Abraham Lincoln
September 29 – Prussian prime minister Otto von Bismarck delivers his Blood and Iron speech to the Prussian Landtag.
October 8 – American Civil War: Battle of Perryville – Union forces under General Don Carlos Buell halt the Confederate invasion of Kentucky by defeating troops led by General Braxton Bragg at Perryville, Kentucky.
October 11 – American Civil War: In the aftermath of the Battle of Antietam, Confederate General J. E. B. Stuart and his men loot Chambersburg, Pennsylvania, during a raid into the North.
October 23 – Otto is deposed as King of Greece.
October 24 – Ramón Castilla loses the Presidency of Peru for a second time.
October 25 – In the Granadine Confederation, rebel troops of the southern states defeat government forces.
November 4 – Richard Jordan Gatling patents the Gatling gun in the United States.
American Civil War: President Abraham Lincoln removes George B. McClellan as commander of the Union Army.
American Indian Wars: In Minnesota, more than 300 Santee Sioux are found guilty of rape and murder of white settlers and are sentenced to hang.
November 14 – American Civil War: President Abraham Lincoln approves the plan by General Ambrose Burnside to capture the Confederate capital city of Richmond, Virginia. This plan leads to a disastrous Union defeat at the Battle of Fredericksburg on December 13).
American Civil War – Battle of Cane Hill: Union Army troops led by General John Blunt push back Confederate troops commanded by General John Marmaduke into northwestern the Boston Mountains of Arkansas.
Notts County F.C. is founded in Nottingham, England, making it (by the 21st century) the world's oldest Association football playing professionally.
December – Peruvian slave raiders land on Easter Island, beginning a decade of the destruction of society and population on the island.
December 1 – In his State of the Union address, President Abraham Lincoln reaffirms the necessity of ending slavery as he ordered ten weeks earlier in his Emancipation Proclamation.
December 2 – The first United States Navy hospital ships enter service.
December 12 – American Civil War: Yazoo Pass Expedition – Union ironclad gunboat USS Cairo is sunk by a remotely-detonated "torpedo" (naval mine) while clearing mines from the Yazoo River, the first armored ship sunk by mine.
December 13 – American Civil War: Battle of Fredericksburg – The Union Army suffers massive casualties and abandons its attempts to capture the Confederate capital city of Richmond, Virginia.
December 17 – General Order No. 11, which expels all Jews from his military district, is issued by General Ulysses S. Grant. This order is rescinded just a few weeks later.
December 26 – William D. Duly hangs 38 Dakota Sioux Indians in Minnesota.
December 26–29 – American Civil War – Battle of Chickasaw Bayou: Another victory for the Confederate Army, outnumbered two to one, results in six times as many Union casualties, defeating several assaults commanded by the Union general, William T. Sherman.
December 30 – The USS Monitor sinks in storm in the Atlantic off Cape Hatteras, North Carolina.
December 31 – American Civil War: President Abraham Lincoln signs an act that admits West Virginia to the Union, thus dividing Virginia into two. Meanwhile, the Battle of Stones River opens near Murfreesboro, Tennessee.
Anna Leonowens accepts an offer made by the Siamese consul in Singapore, Tan Kim Ching, to teach the wives and children of Mongkut, the King of Siam.
Donald McIntyre builds a settlement in northwest Queensland (Australia) which becomes the town of Julia Creek (named after his niece).
January 9 – Carrie Clark Ward, American silent film character actress (d. 1926)
January 15 – Loie Fuller, American dancer (d. 1928)
January 23 – David Hilbert, German mathematician (d. 1943)
January 24 – Edith Wharton, American fiction writer (d. 1937)
January 29 – Frederick Delius, English composer (d. 1934)
January 30 – Walter Damrosch, German-born American orchestral conductor (d. 1950)
February 2 – George Arthur Boeckling, German businessman and the president of Cedar Point Pleasure Company (d. 1931)
February 3 – James Clark McReynolds, Associate Justice of the Supreme Court of the United States (d. 1946)
February 4 – George Ernest Morrison, Australian adventurer and journalist (d. 1920)
February 7 – Bernard Maybeck, American Arts and Crafts architect (d. 1957)
February 8 – Ferdinand Ferber, French Army captain and aviation pioneer (d. 1909)
February 17 – Edward German, English composer (d. 1936)
February 25 – Stanisław Głąbiński, Polish politician, academic, lawyer and writer (d. 1941)
March 4 – Jacob Robert Emden, Swiss astrophysicist and meteorologist (d. 1940)
March 8 – George Frederick Phillips, Canadian-born military hero (d. 1904)
March 13 – Jane Delano, American founder of the American Red Cross Nursing Service (d. 1919)
March 14 – Vilhelm Bjerknes, Norwegian physicist and meteorologist (d. 1951)
March 17 – Silvio Gesell, German economist (d. 1930)
William E. Johnson, American leader of the Anti-Saloon League (d. 1950)
George Sutherland, American politician and Associate Justice of the Supreme Court of the United States (d. 1942)
March 28 – Aristide Briand, French politician, winner of the Nobel Peace Prize (d. 1932)
March 29 – Adolfo Müller-Ury, Swiss-born American painter (d. 1947)
April 2 – Nicholas Murray Butler, American president of Columbia University and winner of the Nobel Peace Prize (d. 1947)
April 6 – Georges Darien, French writer (d. 1921)
April 11 – Charles Evans Hughes, American jurist and politician, Chief Justice of the United States (d. 1948)
April 26 – Edmund C. Tarbell, American Impressionist painter (d. 1938)
April 27 – Rudolph Schildkraut, Istanbul born American actor (d. 1930)
May 8 – Emilie Rathou, Swedish Social Democrat, temperance- and women's right activist (d. 1948)
May 15 – Arthur Schnitzler, Austrian dramatist and narrator (d. 1931)
May 27 – John Kendrick Bangs, American author and satirist (d. 1922)
June 5 – Allvar Gullstrand, Swedish ophthalmologist, winner of the Nobel Prize in Physiology or Medicine (d. 1930)
June 7 – Philipp Lenard, Hungarian–German physicist, winner of the Nobel Prize in Physics (d. 1947)
June 10 – John de Robeck, British admiral (d. 1928)
June 21 – Damrong Rajanubhab, Thai prince and historian (d. 1943)
June 27 – May Irwin, Canadian actress and singer (d. 1938)
William Henry Bragg, English physicist, Nobel Prize laureate (d. 1942)
Christopher Cradock, British admiral (d. 1914)
July 14 – Gustav Klimt, Austrian artist (d. 1918)
July 15 – Ernest Troubridge, British admiral (d. 1926)
July 16 – Ida B. Wells, American journalist, suffragist, and anti-lynching crusader (d. 1931)
August 5 – Joseph Merrick, the "Elephant Man", English sufferer from deformities (d. 1890)
August 16 – Amos Alonzo Stagg, American football player and coach (d. 1965)
August 21 – Emilio Salgari, Italian writer (d. 1911)
August 22 – Claude Debussy, French composer (d. 1918)
August 26 – Herbert Booth, English-born Salvationist, third son of William and Catherine Booth (d. 1926)
Andrew Fisher, Scottish-born fifth Prime Minister of Australia (d. 1928)
Maurice Maeterlinck, Belgian writer, Nobel Prize laureate (d. 1949)
Julian Byng, 1st Viscount Byng of Vimy, British general, 12th Governor General of Canada (d. 1935)
Hawley Harvey Crippen, American-born medical practitioner and uxoricide (hanged 1910)
O. Henry, born William Sydney Porter, American short-story writer (d. 1910)
September 12 – Carl Eytel, German-American artist working in Palm Springs, California (d. 1925)
September 19 – Arvid Lindman, Swedish admiral, industrialist, and politician (d. 1936)
September 23 – Denis Auguste Duchêne, French general (d. 1950)
September 25 – Billy Hughes, seventh Prime Minister of Australia (d. 1952)
September 27 – Louis Botha, Boer general and first Prime Minister of South Africa (d. 1919)
October 3 – Johnny Briggs, English cricketer (d. 1902)
October 12 – Theodor Boveri, German biologist (d. 1915)
October 18 – Mehmet Esat Bülkat, Ottoman general (d. 1952)
October 19 – Auguste Lumière, French inventor (d. 1954)
Hilma af Klint, Swedish abstract painter (d. 1944)
Thomas J. Preston, Jr., American Professor of Archeology at Princeton University, second husband of Frances Cleveland, widow of President Grover Cleveland (d. 1955)
October 27 – Hugh Evan-Thomas, British admiral (d. 1928)
November 3 – Henry George, Jr., American politician (d. 1916)
November 14 – George Washington Vanderbilt II, American businessman (d. 1914)
November 15 – Gerhart Hauptmann, German writer, Nobel Prize laureate (d. 1946)
November 16 – Charles Turner, Australian cricketer (d. 1944)
November 19 – Billy Sunday, American baseball player, evangelist and prohibitionist (d. 1935)
November 23 – Ernest Guglielminetti, Swiss physician (d. 1943)
November 24 – Konrad Krafft von Dellmensingen, Bavarian general (d. 1953)
December 5 – William Walker Atkinson, American spiritual writer (d. 1932)
December 8 – Georges Feydeau, French playwright (d. 1921)
December 12 – J. Bruce Ismay, English shipping magnate, White Star Line (d. 1937)
December 15 – Adrien Loir, French biologist and bacteriologist (d. 1941)
December 17 – Moriz Rosenthal, Polish pianist (d. 1946)
December 25 – Wilhelm Weinberg, German physician (d. 1937)
January 10 – Samuel Colt, American firearms inventor (b. 1814)
January 18 – John Tyler, 10th President of the United States (b. 1790)
February 3 – Jean-Baptiste Biot, French physicist, astronomer and mathematician (b. 1774)
February 7 – Prosper Ménière, French scientist (b. 1799)
Francisco Balagtas, Filipino poet (b. 1788)
William Wallace "Willie" Lincoln, third son of Abraham Lincoln and Mary Todd Lincoln (b. 1850)
February 21 – Justinus Kerner, German physician (b. 1786)
February 24 – Bernhard Severin Ingemann, Danish novelist and poet (b. 1789)
March 22 – Manuel Robles Pezuela, former President of Mexico (executed) (b. 1817)
April 6 – Albert Sidney Johnston, American Confederate general (b. 1803)
April 10 – W. H. L. Wallace, American Civil War general (b. 1821)
April 19 – Louis P. Harvey, Governor of Wisconsin (b. 1820)
May 6 – Henry David Thoreau, American author and philosopher (b. 1817)
May 16 – Edward Gibbon Wakefield, English theorist of colonization. (b. 1796)
May 21 – John Drew Sr., Irish American actor and manager (b. 1827)
May 25 – Juana Azurduy de Padilla, South American guerrilla military leader (b. c. 1781)
June 17 – Charles Canning, 1st Earl Canning, English Viceroy of India (b. 1812)
July 24 – Martin Van Buren, 8th President of the United States (b. 1782)
August 10 – Shusaku Honinbo, Japanese Go player (b. 1829)
August 18 – Simon Fraser, Canadian explorer (b. 1776)
August 20 – Javiera Carrera, Chilean independence fighter (b. 1771)
September 6 – John Sumner, Archbishop of Canterbury (b. 1780)
September 10 – Carlos Antonio López, president of Paraguay (b. 1792)
September 14 – Charles Lennox Richardson, English merchant murdered in Japan (b. 1834)
October 15 – Hans Daniel Ludwig Friedrich Hassenpflug, German statesman (b. 1794)
November 13 – Ludwig Uhland, German poet (b. 1787)
December 13 – Thomas Reade Rootes Cobb, American Confederate general killed during the battle of Fredericksburg (b. 1823)
December 18 – Barbara Fritchie, American Civil War patriot (b. 1766)
1862 (MDCCCLXII) was a common year starting on Wednesday (dominical letter E) of the Gregorian calendar and a common year starting on Monday (dominical letter G) of the Julian calendar, the 1862nd year of the Common Era (CE) and Anno Domini (AD) designations, the 862nd year of the 2nd millennium, the 62nd year of the 19th century, and the 3rd year of the 1860s decade. As of the start of 1862, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localized use until 1923. This year was named by Mitchell Stephens as the greatest year to read newspapers.