| January 1 | 1st U.S. income tax (3% of incomes > $600, 5% of incomes > $10,000) |
| January 1 | Battle of Ft. McRee, Florida Battle of Port Royal, South Carolina (Port Royal Ferry) |
| January 3 | Romney Campaign-Stonewall Jackson moves north from Winchester |
| January 4 | Battle of Helena, AK |
| January 4 | Romney Campaign-Stonewall Jackson occupies Bath |
| January 7 | Battle of Manassas Junction, VA |
| January 7 | Romney Campaign-Stonewall Jackson march towards Romney, WV |
| January 10 | Battle of Big Sandy River, Kentucky (Middle Creek) |
| January 10 | Battle of Romney, WV |
| January 17 | BBT Ft. Henry, Tennessee by USS Lexington |
| January 18 | Confederate Territory of Arizona forms |
| January 19 | Battle of Mill Springs, Kentucky (Fishing Creek, Logan's Crossroads) |
| January 22 | Confederate government raises premium for volunteers from $10 to $20 |
| January 23 | Agoston Haraszthy, 1st vintner in Sonoma Valley, imports 10,000 |
| January 24 | Romania principality arises under King Alexander Cuza |
| January 26 | Lincoln issues General War Order #1, calling for a Union offensive McClellan ignores order |
| January 30 | U.S. Navy's 1st ironclad warship, the Monitor, launched |
| January 31 | Telescope maker Alvin Clark discovers dwarf companion of Sirius |
| February 1 | Julia Howe publishes "Battle Hymn of Republic" |
| February 6 | General Ulysses S. Grant captures Fort Henry in Tennessee |
| February 6 | Naval Engagement at Tennessee River - USS Conestago vs CSS Appleton Belle |
| February 6 | Ulysses S. Grant begins military campaign in Mississippi |
| February 7 | Federal fleet attack on Roanoke Island NC |
| February 8 | Battle of Roanoke Island NC, Federals gain control of Pamlico Sound |
| February 8 | Opera "Lily of Killarney," premieres in London |
| February 10 | Dutch 2nd government of Thorbecke forms |
| February 14 | Galena, 1st U.S. iron-clad warship for service at sea, launched, Connecticut |
| February 15 | Grant's major assault on Ft. Donelson, Tennessee |
| February 16 | Ft. Donelson captured by General Grant (1,400 confederates surrender) |
| February 21 | Confederate Constitution and presidency are declared permanent |
| February 21 | Texas Rangers win Confederate victory at Battle of Val Verde, New Mexico |
| February 25 | Congress forms U.S. Bureau of Engraving and Printing |
| February 25 | Paper currency introduced in U.S. by President Abraham Lincoln |
| February 26 | Battle of Woodburn, Kentucky |
| February 28 | Opera "La Reine de Saba," premieres in Paris |
| March 3 | Battle of New Madrid MO-captured by Union forces |
| March 3 | General Pope lays siege in front of New Madrid |
| March 5 | Union troops under Brigadier-General Wright occupy Fernandina Florida |
| March 6 | Battle of Pea Ridge, AR (Elkhorn Tavern) |
| March 7 | Battle of Elkhorn Tavern, Day 2, Gens McCulloch and McIntosh killed |
| March 8 | Battle of Elkhorn Tavern ends with Confederate withdrawal |
| March 8 | Confederate ironclad "Merrimack" launched |
| March 8 | Naval Engagement at Hampton Roads, Virginia CSS Virginia, Jamestown and Yorktown vs USS Cumberland, Congress and Monitor |
| March 9 | "Monitor" (Union) and "Merrimack" (Rebel) battle in Hampton Roads |
| March 10 | Great Britain and France recognizes independence of Zanzibar |
| March 10 | U.S. issues 1st paper money ($5, $10, $20, $50, $100, $500 and $1000) |
| March 11 | General Stonewall Jackson evacuates Winchester Virginia Army of the Potomac, General Henry Halleck is named general-in-chief |
| March 14 | Battle of New Bern NC: General Burnside conquers New Bern |
| March 15 | General John Hunt Morgan begins 4 days of raids near Gallatin, Tennessee |
| March 16 | Battle at Pound Gap Kentucky: Confederates separate battles |
| March 22 | San Marino and Italy conclude treaty of friendship and cooperation |
| March 23 | Battle of Kernstown VA-Jackson begins his Valley Campaign |
| March 26 | Battle of La Glorieta Pass, New Mexico Territory (Apache Canyon, Pigeon's Ranch) |
| March 28 | Skirmish at Bealeton Station, Virginia |
| March 31 | Civil War action at Island #10 on Mississippi River |
| April 1 | Shenandoah Valley campaign, Jackson's Battle of Woodstock, VA |
| April 4 | Battle of Yorktown begins |
| April 4 | U.S. begins Peninsular Campaign aimed at capturing Richmond |
| April 5 | Siege of Yorktown, Virginia |
| April 6 | Battle of Shiloh, Union defeats Confederacy in SW Tennessee |
| April 7 | Grant defeats Confederates at Battle of Shiloh, Tennessee, Island #10 falls |
| April 8 | John D. Lynde patents aerosol dispenser |
| April 11 | Rebels surrender Ft. Pulaski, Georgia-Rebels surrender |
| April 12 | James Andrews steals Confederate train (General) at Kennesaw, Georgia |
| April 12 | Union troops occupy Fort Pulaski Georgia |
| April 14 | Battle of Ft. Pillow Tennessee |
| April 16 | Slavery abolished in District of Columbia |
| April 16 | U.S. Confederate Congress calls up all white males (18-35 years) |
| April 18 | Battle of Ft. Jackson, Ft. St. Philip and New Orlean's, Louisiana |
| April 21 | Congress establishes U.S. Mint in Denver, Colorado |
| April 21 | Ellen Price Wood's "East Lynne, premieres in Boston |
| April 25 | Battle of New Orleans LA - U.S. Admiral Farragut occupies New Orleans |
| April 29 | 100,000 federal troops prepare to march into Corinth, Mississippi |
| April 29 | New Orleans fell to Union forces during Civil War |
| April 30 | Swift Run Gap, West Virginia skirmishes |
| May 1 | Union captain David Farragut conquers New Orleans |
| May 4 | Battle at Williamsburg, Virginia |
| May 4 | Yorktown, Virginia - McClellan halted his troop before town as it is full of armed torpedoes left by CS Brigadier General Gabrial Rains |
| May 5 | French army intervenes in Puebla, Mexico: Cinco de Mayo |
| May 5 | Peninsular Campaign-Battle of Williamsburg, Virginia |
| May 7 | Battle of West Point, Virginia (Eltham's Landing, Barnhamsville) |
| May 7 | Much of Enschede Netherlands destroyed by fire |
| May 8 | Valley Campaign: Federals repulsed at Battle of McDowell Va |
| May 9 | Battle of Farmington, Mississippi |
| May 9 | Battle of Ft. Pickens, Florida (Pensacola), evacuated by CS |
| May 9 | U.S. Naval Academy relocated from Annapolis Maryland to Newport, Rhode Island |
| May 10 | Battle of Plum Run Bend, Tennessee (Plum Point Bend) |
| May 11 | Confederates scuttle CSS Virginia off Norfolk, Virginia |
| May 12 | Federal troops occupies Baton Rouge Louisiana |
| May 14 | Adolphe Nicole of Switzerland patents chronograph |
| May 15 | Battle of Drewry's Bluff (Ft. Darling), Virginia |
| May 15 | Confederate cruiser The Alabama runs aground near London |
| May 15 | Department of Agriculture created |
| May 15 | General Benjamin F Butler delegates "Woman Order" of NO to be his whores |
| May 15 | Union Grounds, Brooklyn, 1st baseball enclosure, opens |
| May 16 | Jean Joseph Etienne Lenoir builds 1st automobile |
| May 17 | Battle of Princeton, West Virginia, ends, about 128 casualities |
| May 19 | Homestead Act becomes law provides cheap land for settlement of West |
| May 23 | Battle at Front Royal, Virginia |
| May 23 | Valley Campaign-Stonewall Jackson takes Ft. Royal, Virginia |
| May 24 | Beardslee field telegraph used for 1st time |
| May 24 | Westminster Bridge across Thames opens |
| May 25 | Battle of Winchester, Virginia |
| May 27 | Battle of Hanover Court House, Virginia (Slash Church, Peake's Station) |
| May 30 | Battle of Booneville, Mississippi - captured General Beauregard evacuates Corinth |
| May 30 | Battle of Front Royal, Virginia |
| May 31 | Battle of Seven Pines Virginia (Fair Oaks) |
| June 1 | 2nd/last day of battle at Fair Oaks/7 Pines Virginia (11,165 casualties) |
| June 1 | General Lee assumes command after Joe Johnston is injured at 7 Pines |
| June 1 | Slavery abolished in all U.S. possessions |
| June 2 | General Robert E Lee takes command of Confederate armies of E Virginia and NC |
| June 2 | Raid at Early's: Maryland towards Washington D.C. |
| June 4 | Confederates evacuate Ft. Pillow, Tennessee |
| June 6 | Battle of Memphis-city is surrendered |
| June 6 | Battle of Port Royal, South Carolina, Port Royal Ferry |
| June 6 | Skirmish at Harrisonburg, Pennsylvania |
| June 7 | General B. Butler orders William Mumford hanged after he removed and destroyed U.S. flag on display over New Orleans Mint |
| June 7 | Skirmish at Union Church, Virginia (Peninsular) |
| June 8 | Valley Campaign-Battle of Cross Keys, Virginia |
| June 9 | Battle of Port Republic, last of 5 battles in Jacksons Valley camp |
| June 15 | General JEB Stuart completes his "ride around McClellan" |
| June 19 | Slavery outlawed in U.S. territories |
| June 25 | Battle of Oak Grove, Virginia (Orchard, Henrico, French's Field) (Kings's Schoolhouse) Day 1 of 7 Days |
| June 26 | Battle of Beaver Dam Creek-Union repulses Confederacy in Virginia |
| June 26 | Day 2 of 7 Days-Battle of Mechanicsville Virginia (Meadow Bridge) |
| June 26 | U.S. Army of Virginia established under General John Pope |
| June 27 | Battle at Garnett's/Golding's Farms, Virginia |
| June 27 | Battle of Gaines' Mill, Virginia (Cold Harbor, Chickahominy Bluffs) Day 3 |
| June 28 | Day 4 of 7 Days-Battle of Savage's Station/Garnett's Farm, Virginia |
| June 29 | Day 5 of 7 Days-Battle of Savage's Station, Virginia |
| June 30 | Battle at Nelson's Farm, Virginia |
| June 30 | Battle at Turkey Bridge Virginia: Confederate assault attack |
| June 30 | Day 6 of 7 Days-Battle of White Oak Swamp Virginia (Frayser's Farm) |
| June 30 | Gustave Flaubert completes "Salammbo" |
| July 1 | Battle at Booneville Mississippi: Confederate superior power driven out |
| July 1 | Battle of Holly Spring, MS |
| July 1 | Battle of Malvern Hill, Virginia (Harrison's Landing, Crew's Farm) |
| July 1 | Congress outlaws polygamy (1st time); bad news for Utah |
| July 1 | Day 7 of 7 Days-Battle of Malvern Hill (Poindexter's Farm) Day 7 of Seven Days US15,249 CS17,583 |
| July 1 | Emperor Alexander II grants Jews right to publish books |
| July 1 | Internal Revenue Law imposes 1st federal taxes on inheritance, tobacco and on incomes over $600 (progressive rate) |
| July 2 | Lincoln signs act granting land for state agricultural colleges |
| July 4 | Battle at Green River Kentucky (Morgan's Ohio Raid) |
| July 4 | Battle of Port Royal, South Carolina (Port Royal Ferry) |
| July 4 | Lewis Carroll creates Alice in Wonderland for Alice P. Liddell |
| July 6 | Skirmish at Devall's Bluff Arkansas (106 casualties) |
| July 7 | Land Grant Act endows state colleges with federal land |
| July 8 | Odore R Timby patents revolving gun turret |
| July 9 | General John Hunt Morgan captures Tompkinsville, Kentucky |
| July 10 | U.S. begins construction of Central Pacific Railroad |
| July 11 | Lincoln appoints General Halleck general-in-chief |
| July 12 | Congress authorizes Medal of Honor |
| July 12 | Federal troops occupy Helena, Arkansas |
| July 13 | Battle of Murfreesboro, Tennessee (Forrest's Raid) US895 CS150 |
| July 15 | CSS Arkansas vs USS Cardondelet and Queen of the West engage at Yazoo R |
| July 16 | David G Farragut is 1st rear Admiral in U.S. Navy |
| July 17 | Naval Engagement at Pascagoula River MS: USS Potomac Expedition |
| July 17 | R John Hunt Morgan:Cynthiana, Kentucky CS24 US17 Skirmish at Columbia, Tennessee |
| July 17 | U.S. Army authorized to accept blacks as laborers |
| July 17 | United army officially divides corps |
| July 18 | Battle of Newburgh, IN - captured by Union forces |
| July 19 | Forrest's 1st raid |
| July 27 | Hurricane hits Canton; about 40,000 die |
| July 27 | Steamer "Golden Gate" burns and sinks off west coast of Mexico |
| July 28 | Confederate forces defeated at More's Hill, Mo |
| August 4 | U.S. government collects its 1st income tax |
| August 5 | Battle of Baton Rouge, LA |
| August 6 | Confederate Army ironclad "Arkansas" is badly damaged in Union attack |
| August 9 | Battle of Cedar Mountain Virginia (Slaughter Mountain, Southwest Mountain) |
| August 9 | Berlioz' opera "Beatrice et Benedict," premieres in Baden-Baden |
| August 9 | Prelude to 2nd Manassas, Jackson is victorious at Battle of Cedar Mt., however General Charles S. Winder is killed |
| August 10 | Battle of Nueces River, Texas |
| August 12 | General John Hunt Morgan and his raiders capture Gallatin, TX |
| August 14 | Lincoln receives 1st group of blacks to confer with U.S. president |
| August 17 | Confederate troops under Kirby Smith enter Kentucky |
| August 18 | General Lee's adjutant major Stuart captured |
| August 18 | Sioux Indians begin uprising in Minnesota |
| August 22 | Battle of Catlett's Station VA |
| August 22 | Santee Sioux indian attack Fort Ridgely |
| August 23 | Skirmish at Big Hill, Kentucky (2 Federal regiments) |
| August 25 | Secretary of War authorizes General Rufus Saxton to arm 5,000 slaves |
| August 28 | Battle of Thoroughfare Gap VA |
| August 28 | Belle Boyd released from Old Capital Prison in Washington, D.C. |
| August 29 | 2nd Battle of Bull Run (Manassas) begins |
| August 29 | Battle of Aspromonte-Italian royal forces defeat rebels |
| August 29 | Battle of Bull Run, Virginia (Manassas, Gainesville, Bristoe Station) |
| August 29 | U.S. Bureau of Engraving and Printing begins operation |
| August 30 | 2nd Battle of Bull Run - Confederates beat Union |
| August 30 | Battle of 2nd Manassas-Pope defeated by Lee-Battle of Richmond, Kentucky |
| August 30 | Battle of Altamont-Confederates beat Union forces in Tennessee |
| September 1 | Battle at Chantilly (Ox Hill) Virginia (2100 casualties) |
| September 1 | Federal tax levied on tobacco |
| September 4 | General Lee invades North with 50,000 Confederate troops |
| September 4 | North Beach and Mission Railway Company organized in SF |
| September 5 | Lee crosses Potomac and enters Maryland |
| September 6 | Stonewall Jackson occupies Frederick, Maryland |
| September 9 | Lee splits his army and sends Jackson to capture Harpers Ferry |
| September 12 | Battle of Harpers Ferry VA |
| September 14 | Battle at Crampton's Gap: Union troops chases away Confederates |
| September 14 | Battle at South Mountain: Union troops chases away Confederates |
| September 14 | Battle of Munfordsville, Kentucky |
| September 14 | Federal troops escape from beleaguered Harpers Ferry West Virginia |
| September 14 | Skirmish at Mountain MD (Boonesboro, Crampton's Gap, Fox's Gap) |
| September 15 | Confederates conquer Union-weapon arsenal at Harpers Ferry WV |
| September 16 | Battle of Antietam, bloodiest day in Civil War (Sharpsburg Md) |
| September 16 | General Bragg's army surrounds 4,000 federals at Munfordville, Kentucky |
| September 16 | Liliuokalani, queen of Hawaii (1891-93) marries John Owen Dominis |
| September 17 | Battle of Cumberland Gap, TN-evacuted by Federals |
| September 17 | Battle of Mumfordville, Kentucky-U.S. Col J Wilder surrenders city |
| September 17 | Battle of Sharpsburg (Antietam)-bloodiest day of Civil War, 23,110 die |
| September 18 | Confederate armies officially divide into corps |
| September 18 | General Read army pulls out of Antietam Creek Virginia |
| September 19 | Battle at Blackford's Ford Virginia |
| September 19 | Battle at Iuka Mississippi (1,700 casualties) |
| September 22 | President Lincoln, says he will free slaves in all states on Jan 1 |
| September 23 | Lincoln's Emancipation is published in Northern Newspapers |
| September 24 | Confederate Congress adopts confederacy seal |
| September 25 | Skirmish at Davis' Bridge, Tennessee |
| October 3 | Battle of Corinth, Mississippi |
| October 3 | Skirmish at Bardstown, Kentucky |
| October 4 | Battle of Corinth ends |
| October 5 | Battle of Big Hatchie River, MS |
| October 5 | Federal fleet occupies Galveston, Texas |
| October 8 | Battle of Perryville, Kentucky-Confederate invasion halted |
| October 8 | Otto von Bismarck becomes German republic chancellor |
| October 12 | JEB Stuart completes his "2nd ride around McClellan" |
| October 12 | Major General Earl Van Dorn assumes command of Confederate troops in Missisippi |
| October 12 | Skirmish at Monocacy, Maryland |
| October 13 | Bismarck's "Blood and Iron" speech |
| October 14 | Baseballer James Creighton ruptures bladder hitting home run, dies 10/18 |
| October 14 | Excelsiors defeat Unions of Morrisania 13-9 |
| October 17 | Battle of Leetown and Thoroughfare Gap, VA |
| October 18 | Morgan's raiders capture federal garrison at Lexington, Kentucky |
| October 20 | Amnesty proclaimed for escaped slaves of Suriname |
| October 22 | Battle at Old Fort Wayne, Indian Territory |
| October 22 | Confederate troops reconquer Cumperland Gap, Tennessee |
| October 30 | Dr. Richard Gatling patents machine gun |
| November 3 | Battle between gunboats at Bayou Teche, Louisiana |
| November 3 | Dr. Richard Gatling patents machine gun (Indianapolis) |
| November 4 | Richard Gatling patents Gatling gun |
| November 5 | Ambrose Burnside replaces McClellen as head of Army of Potomac |
| November 5 | Battle at Barbee's Crossroads, Virginia: 51 casualties |
| November 6 | NY-SF direct telegraphic link forms |
| November 9 | U.S. Grant issues orders to bar Jews from serving under him |
| November 11 | Opera "La Forza Del Destino" is produced (St. Petersburg Russia) |
| November 13 | Battle of Holly Spring, MS |
| November 17 | Confederate Secretary of War George B. Randolph resigns |
| November 20 | Armies of Mississippi/Kentucky merge as Army of Tennessee |
| November 20 | Confederate army of Tennessee, organizes under General Braxton Bragg |
| November 24 | M Levy publishes Gustave Flauberts "Salammbo" |
| November 28 | Battle at Cane Hill, Arkansas (475 casualties) |
| November 28 | Battle of Hooly Spring, MS |
| December 5 | Battle of Coffeeville, MS |
| December 6 | President Lincoln orders hanging of 39 Santee Sioux indians |
| December 7 | Battle of Hartsville, TN |
| December 7 | Battle of Prairie Grove, AR |
| December 12 | Battle of Dumfries, VA |
| December 12 | Battle of Fredericksburg, Virginia (Marye's Heights) |
| December 12 | Naval Engagement at Yazoo River, MS (USS CAIRO torpedoed) |
| December 16 | Kingdom of Nepal accepts its constitution |
| December 17 | General U.S. Grant issues order #11, expelling Jews from Tennessee |
| December 18 | Battle at Lexington, Tennessee (Forrest's Second Raid) |
| December 19 | Skirmish at Jackson/Salem Church, Tennessee (80 casualties) |
| December 20 | Battle of Holly Spring, MS |
| December 20 | Brigadier-General Nathan Bedford Forrest occupies Trenton, Kentucky |
| December 23 | Union General Ben "Beast" Butler is proclaimed a "felon, outlaw and common enemy of mankind" by Jefferson Davis |
| December 25 | 40,000 watch Union army men play baseball at Hilton Head, SC |
| December 26 | 1st U.S. Navy hospital ship enters service |
| December 26 | 38 Santee Sioux Indians hanged in Mankato Minn, due to their uprising |
| December 26 | Battle of Dumfries, VA |
| December 27 | Battle of Chickasaw Bluffs, MS (Chickasaw Bayou) |
| December 27 | Battle of Elizabethtown, Kentucky |
| December 29 | Battle of Chichasaw Bayou: confederate armies defeat General Sherman |
| December 29 | Bowling ball invented |
| December 31 | Battle of Murfreesboro, Tennessee |
| December 31 | Battle of Stone's River, Tennessee (Stone River, Monfreesboro) |
| December 31 | President Lincoln signs act admitting West Virginia to Union |
| December 31 | Skirmish at Parker Cross Roads, Tennessee |
| December 31 | Union ironclad ship "Monitor" sank off Cape Hatteras, NC |
