1859 1860 1861 - 1862 - 1863 1864 1865
1830s 1840s 1850s - 1860s - 1870s 1880s 1890s
18th century - 19th century - 20th century
- January 10 - End of term for John Gately Downey, 7th Governor of California. He is succeeded by Amasa Leland Stanford.
- January 30 - The first American ironclad warship, the USS Monitor is launched.
- February 1 - Julia Ward Howe's "Battle Hymn of the Republic" is published for the first time (Atlantic Monthly).
- February 6 - American Civil War: Ulysses S. Grant gives the United States its first victory of the war, by capturing Fort Henry, Tennessee
- February 15 - American Civil War: General Ulysses S. Grant attacks Fort Donelson, Tennessee and captures it the next day.
- February 22 - American Civil War: Jefferson Davis officially inagurated in Richmond, Virginia, to a six-year term as president of the Confederate States of America.
- March 8 - American Civil War: The iron-clad CSS Virginia (formerly USS Merrimack) is launched at Hampton Roads, Virginia.
- March 9 - American Civil War: First battle between two ironclad warships USS Monitor v CSS Virginia
- 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.
- April 5 - American Civil War: Battle of Yorktown - The battle begins when Union forces under General George 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 - Union Army under General Ulysses S. Grant defeats the Confederates near Shiloh, Tennessee.
- May 5 - Battle of Puebla, Mexican General Ignacio Zaragoza defeats the French Army; commemorated as the Cinco de Mayo.
- 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 United States Bureau of Agriculture (later renamed USDA).
- May 20 - U.S. President Abraham Lincoln signs the Homestead Act into law.
- June 1 - American Civil War: Battle of Fair Oaks ends - Both sides claim victory.
- June 4 - American Civil War: Confederate troops evacuate Fort Pillow on the Mississippi River, leaving the way clear for Union troops to take Memphis, Tennessee.
- June 6 - American Civil War: Battle of Memphis - Union forces capture Memphis, Tennessee from the Confederates
- June 8 - American Civil War: Battle of Cross Keys - Confederate forces under General Stonewall Jackson save the Army of Northern Virginia from a Union assault on the James Peninsula led by General George McClellan.
- July 1 - Marriage of Princess Alice, second daughter of Queen Victoria to Prince Ludwig of Hesse and by Rhine.
- July 1 - United States president Abraham Lincoln signs into law the Pacific Railway Acts authorizing construction of the First Transcontinental Railroad.
- July 16 - American Civil War: David G. Farragut becomes the first United States Navy rear admiral.
- July 19 - American Civil War: Morgan's Raid - At Buffington Island in Ohio, Confederate General John Hunt Morgan's raid into the north is mostly thwarted when a large group of his men are captured while trying to escape across the Ohio River.
- 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 17 - Indian Wars: Lakota (Sioux) uprising begins in Minnesota as desperate Lakota attack white settlements along the Minnesota River. They will be overwhelmed by the US military six weeks later.
- August 19 - Indian Wars: 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 28-August 30 - American Civil War: Second Battle of Bull Run
- 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: President Abraham Lincoln reluctantly restores Union General George McClellan to full command after General John Pope's disastrous defeat at the Battle of Second 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 17 - Union forces defeat Confederate troops at the Battle of Antietam, in the bloodiest day in the American Civil War (with over 20,000 casualties).
- September 22 - Otto von Bismarck becomes prime minister of Prussia.
- September 22 – Emancipation Proclamation
- September 29 - Bismarck's "Blood and Iron" speech
- 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.
- November 5 - American Civil War: Abraham Lincoln removes George McClellan as commander of the Union Army.
- November 5 - 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: Union President Abraham Lincoln approves General Ambrose Burnside's plan to capture the Confederate capital at Richmond, Virginia (this led to a dramatic Union defeat at the Battle of Fredericksburg on December 13).
- November 28 - American Civil War: Battle of Cane Hill - Union troops led by General John Blunt push back Confederate forces commanded by General John Marmaduke into northwestern Arkansas' Boston Mountains.
- December 2 - First US Navy hospital ships enter service
- December 18 - General Order No. 11 is issued by General Ulysses S. Grant.
- December 26 – William D. Duly hangs 38 Dakota Sioux in Minnesota
- December 30 - The USS Monitor sinks off Cape Hatteras, North Carolina
- December 31 - American Civil War: Abraham Lincoln signs an act that admits West Virginia to the Union (thus dividing Virginia in two).
- Richard Jordan Gatling patents the Gatling gun.
- The United States passes the Morrill Land-Grant Colleges Act
- A smallpox epidemic in California.
- Bureau of Internal Revenue, forefunner of IRS, founded
- Francisco Solano Lopez becomes Paraguayan dictator
- January 15 - Loie Fuller, dancer (d. 1928)
- January 24 - Edith Wharton, writer
- January 29 - Frederick Delius, composer (d. 1934)
- February 4 - George Ernest Morrison, Australian adventurer/journalist (d. 1920)
- March 8 - George Frederick Phillips, military hero (d. 1904)
- March 12 - Jane Delano, founder, American Red Cross Nursing Service (d. 1919)
- March 17 - Silvio Gesell, economist (d. 1930)
- March 28 - Aristide Briand, politician, winner of the 1926 Nobel Prize in peace (d. 1932)
- May 15 - Arthur Schnitzler, dramatist and narrator (d. 1931)
- June 21 - Damrong Rajanubhab, Thai prince, administrator and historian (d. 1943)
- June 27 – May Irwin, actress, singer (d. 1938)
- August 22 - Claude Debussy, French composer
- August 29 - Andrew Fisher, fifth Prime Minister of Australia (d. 1928)
- September 25 - Billy Hughes, seventh Prime Minister of Australia (d. 1952)
- November 14 – George Washington Vanderbilt, businessman (d. 1914)
- December 8 - Georges Feydeau, French playwright (d. 1921)
- January 10 - Samuel Colt, inventor
- January 18 - John Tyler, former President of the United States, member of the Congress of the Confederate States of America
- February 7 - Prosper Meniere, French scientist who first described the symptoms now known as [[M�ni�re's disease]].
- May 6 - Henry David Thoreau, author and philosopher
- July 24 - Martin Van Buren, eighth president of the United States
- August 10 - Shusaku Honinbo, Go player