| January 1 | Porfirio Diaz conquers Mexico City |
| January 2 | Colonel Charles Stone is put in charge of organizing DC militia |
| January 2 | South Carolina seizes inactive Ft. Johnson in Charleston Harbor |
| January 3 | Delaware legislature rejects proposal to join Confederacy |
| January 3 | U.S. Ft. Pulaski and Ft. Jackson, Savannah, seized by Georgia |
| January 4 | President Buchanan appoints a fast on account of threatened succession |
| January 4 | U.S. Ft. Morgan, Mobile, seized by Alabama |
| January 5 | 250 Federal troops are sent from New York to Ft. Sumter |
| January 5 | Alabama troops seize Forts Morgan and Gaines at Mobile Bay |
| January 6 | Florida troops seize Federal arsenal at Apalachicola |
| January 6 | New York City mayor proposes New York become a free city, trading with N and S |
| January 7 | Florida troops takeover Ft. Marion at St. Augustine |
| January 9 | 1st hostile act of Civil War; Star of West fired on, Sumter, SC |
| January 9 | Mississippi becomes 2nd state to secede |
| January 10 | Florida becomes 3rd state to secede from US |
| January 10 | Ft. Jackson and Ft. Philip are taken over by LA state troops |
| January 10 | U.S. forts and property seized by Mississippi |
| January 11 | Alabama becomes 4th state to secede |
| January 11 | Mexico City captured by Juarez (Lib) in War of Reform |
| January 12 | FL state troops demand surrender of Ft. Pickens |
| January 14 | Ft. Pikens, Florida falls into state hands |
| January 15 | Steam elevator patented by Elisha Otis |
| January 17 | Flush toilet patented by Mr. Thomas Crapper (Honest!) |
| January 19 | Georgia becomes 5th state to secede |
| January 19 | MS troops take Ft. Massachusetts an Ship Island |
| January 21 | Jefferson Davis of Mississippi and 4 other southern senators resign |
| January 24 | Arsenal at Augusta, Georgia seized by Confederacy |
| January 24 | Federal troops from Ft. Monroe are sent to Ft. Pikens |
| January 26 | Louisiana becomes 6th state to secede |
| January 29 | Kansas becomes 34th state |
| January 31 | Friedrich Hebbel's "Siegfrieds Tod," premieres in Weimar |
| January 31 | State of Louisiana takes over U.S. Mint at New Orleans |
| February 1 | Dike breaks in Gelderland Netherlands |
| February 1 | Texas becomes 7th state to secede |
| February 4 | Confederate constitutional convention meets for 1st time, Montgomery, Alabama, Ga, Fla, La, Miss and South Carolina elect Jefferson Davis President of Confederacy |
| February 5 | 1st moving picture peep show machine is patented by Samuel Goodale |
| February 5 | Kinematoscope patented by Coleman Sellers, Philadelphia |
| February 5 | Louisiana delegation except Mr. Bouligny withdraws from Congress |
| February 6 | 1st meeting of Provisional Congress of Confederate States of America |
| February 6 | English Admiral Robert Ritzroy issues 1st storm warnings for ships |
| February 8 | Confederate States of America organizes in Montgomery, Alabama |
| February 9 | Confederate Provisional Congress declares all laws under the U.S. Constitution were consistent with constitution of Confederate states |
| February 9 | Jefferson Davis and Alexander Stephens elected president and Vice President of CSA |
| February 9 | Tennessee votes against secession |
| February 11 | President-elect Lincoln takes train from Spingfield Illinois to Washington D.C. |
| February 11 | U.S. House unanimously passes resolution guaranteeing noninterference with slavery in any state |
| February 12 | State troops seize U.S. munitions in Napoleon, Arkansas |
| February 13 | 1st military action to result in Congressional Medal of Honor |
| February 13 | Abraham Lincoln declared president |
| February 13 | Col Bernard Irwin attacks and defeats hostile Chiricahua Indians |
| February 15 | Ft. Point completed and garrisoned (but has never fired cannon in anger) |
| February 18 | Confederate President Jefferson Davis inaugurated at Montgomery Alabama |
| February 18 | King Victor Emmanuel II of Sardinia becomes 1st king of Italy |
| February 19 | Russian Tsar Alexander II abolishes serfdom |
| February 20 | Department of Navy of Confederacy forms |
| February 20 | Steeple of Chichester Cathedral blown down during a storm |
| February 21 | Navaho indians elect Herrero Grande as chief |
| February 22 | On a bet Edward Weston leaves Boston to walk to Lincoln's inauguration |
| February 23 | By popular referendum, Texas becomes 7th state to secede from U.S. |
| February 23 | Dutch Premier Floris A van Hall resigns |
| February 23 | President-elect Lincoln arrives secretly in Washington D.C. to take office |
| February 27 | Russians shoot at Poles protesting Russian rule of Poland |
| February 27 | U.S. Congress authorizes 1st stamped newspaper wrappers for mailing |
| February 27 | Warsaw Massacre: Russians fire on crowd demonstrating against Russia |
| February 28 | Territories of Nevada and Colorado created |
| March 2 | Government Printing Office purchases 1st printing plant, Washington |
| March 2 | U.S. creates Dakota and Nevada Territories out of the Nebraska and Utah territories |
| March 3 | Russian Tsar Alexander II abolishes serfdom |
| March 4 | Confederate States adopt "Stars and Bars" flag |
| March 4 | Lincoln's inaugurated as 16th president |
| March 4 | President Lincoln opens Government Printing Office |
| March 6 | Provisionary Confederate Congress establishes Confederate Army |
| March 8 | St. Augustine Florida surrenders to Union armies |
| March 9 | Confederate currency authorized-$50, $100, $500, $1,000 |
| March 11 | Confederate convention in Montgomery, adopts constitution |
| March 13 | Jefferson Davis signs bill authorizing use of slaves as soldiers |
| March 16 | Arizona Territory votes to leave the Union |
| March 16 | Confederate government appoints commissioners to Britain |
| March 17 | Italy declares independence; Kingdom of Italy proclaimed |
| March 22 | 1st U.S. nursing school chartered |
| March 23 | London's 1st tramcars, designed by Mr. Train of New York, begins operating |
| March 27 | Black demonstrators in Charleston staged ride-ins on street cars |
| March 31 | Confederacy takes over mint at New Orleans |
| April 5 | Federals abandon Ft. Quitman, Texas |
| April 8 | U.S. Mint at Dahlonega, Georgia seized by Confederacy |
| April 12 | Fort Sumter, South Carolina is shelled by Confederacy, starting Civil War |
| April 13 | After 34 hours of bombardment, Ft. Sumter surrenders to Confederates |
| April 14 | Formal Union surrender of Ft. Sumter |
| April 14 | Robert E Lee resigns from Union army |
| April 15 | Federal army (75,000 volunteers) mobilized by President Lincoln |
| April 16 | U.S. president Lincoln outlaws business with confederate states |
| April 17 | Indianola Texas - "Star of West" taken by Confederacy |
| April 17 | Virginia is 8th state to secede |
| April 18 | Battle of Harpers Ferry, Virginia |
| April 18 | Col Robert E. Lee turns down offer to command Union armies |
| April 19 | Baltimore riots-4 soldiers, 9 civilians killed |
| April 19 | Lincoln orders blockade of Confederate ports (Civil War) |
| April 20 | Battle of Norfolk, Virginia |
| April 20 | Colonel Robert E. Lee resigns from Union army |
| April 22 | Robert E. Lee named commander of Virginia Confederate forces |
| April 23 | Arkansas troops seize Ft. Smith |
| April 23 | Battle of San Antonio, Texas |
| April 25 | 7th New York arrives to reinforce Washington, D.C. |
| April 25 | Battle of Lavaca, Texas |
| April 27 | President Abe Lincoln suspends writ of habeas corpus |
| April 27 | West Virginia secedes from Virginia after Virginia secedes from U.S. |
| April 29 | Maryland's House of Delegates votes against seceding from Union |
| April 30 | President Lincoln ordered Federal Troops to evacuate Indian Territory |
| May 1 | Lee orders Confederate troops under T J Jackson to Harper's Ferry |
| May 3 | General Winfield Scott presents his Anaconda Plan |
| May 3 | Lincoln asks for 42,000 Army Volunteers and another 18,000 seamen |
| May 4 | At Gretna LA, one of 1st guns of Rebel Navy is cast |
| May 6 | Arkansas and Tennessee becomes 9th and 10th state to secede from US |
| May 6 | Jefferson Davis approves a bill declaring War between U.S. and Confederacy |
| May 7 | Riot occurs between prosecessionist and Union supporters in Knoxville TN |
| May 8 | Richmond, Virginia, is named the capital of the Confederacy |
| May 10 | Union troops march on state militia in St. Louis, Missouri |
| May 13 | Queen Victoria announces England's position of neutrality |
| May 16 | Confederate government offers war volunteers $10 premium |
| May 16 | Kentucky proclaims its neutrality |
| May 18 | Battle of Sewall's Point VA-1st Federal offense against South |
| May 18 | Friedrich Hebbels "Kriemhildes Rache," premieres in Weimar |
| May 20 | Cornerstone of University of Washington laid in Seattle |
| May 20 | Kentucky proclaims its neutrality in Civil War |
| May 20 | U.S. marshals appropriate previous year's telegraph dispatches, to reveal prosecessionist evidence |
| May 21 | Richmond, Virginia is designated Confederate Capital |
| May 23 | 3 fleeing slaves enter Fort Monroe Virginia |
| May 23 | Virginia citizens vote 3 to 1 in favor of secession |
| May 24 | Alexandria, Virginia occupied by Federal troops |
| May 24 | Major General Benjamin Butler declares slaves "contraband of war" |
| May 25 | John Merryman is arrested under suspension of writ of habeas corpus it later sparks a supreme court decision protecting writ |
| May 26 | Postmaster General Blair announces end of postal connection with South |
| May 26 | Union blockades New Orleans, Louisiana and Mobile Alabama |
| May 29 | Dorothea Dix offers help in setting up hospitals for Union Army |
| May 31 | General Beauregard is given command of Confederate Alexandria Line |
| May 31 | Mint at New Orleans closes |
| June 1 | 1st skirmish in Civil War, Fairfax Court House, Virginia |
| June 1 | British territorial waters and ports off-limits during Civil War |
| June 1 | Skirmish at Arlington Mills, Virginia |
| June 1 | U.S. and Confederacy simultaneously stop mail interchange |
| June 3 | 1st Civil War land battle-Union defeats Confederacy at Philippi, WV |
| June 5 | Federal marshals seize arms and gunpower at Du Pont works DE |
| June 6 | Lincoln's cabinet declares Union government will pay for expenses once states have mobilized volunteers |
| June 8 | People of Tennessee vote to succeed from Union |
| June 8 | U.S. Sanitary Commission is given executive approval |
| June 10 | Battle of Big Bethel Virginia (Bethel Church, Great Bethal)-Union retreats |
| June 12 | Missouri Governor Claiborne Jackson calls for 50,000 volunteers to stop Federates from taking over his state |
| June 14 | Harpers Ferry evacuated by rebels in face of McClellan's advance |
| June 15 | Johnston evacuates Harpers Ferry |
| June 16 | Battle of Vienna, Virginia and Secessionville, South Carolina, James Island |
| June 17 | Battle of Boonville, MI-Brigadier General Lyon defeats Confederate forces |
| June 19 | Anaheim Post Office established |
| June 19 | Francis Pierpont is elected provisional governor of West Virginia |
| June 24 | Battle of Mathias Point, Virginia - U.S. attacks Confederate batteries |
| June 24 | Tennessee becomes 11th (& last) state to secede from US |
| June 25 | Western Virginia campaign |
| June 28 | Leipzig Observatory discovers short-period (6.2 yrs) Comet d'Arrest |
| June 30 | CSS Sumter slips past USS Brooklyn blockade |
| July 1 | 1st public schoolhouse opens at Washington and Mason St, SF |
| July 1 | War Department decrees the KA and Tennessee are to be canvassed for volunteers |
| July 2 | Battle of Hoke's Run, West Virginia - small Union victory |
| July 3 | Colonal Jackson receives his commission as brigadier general |
| July 3 | Martinsburg, Virginia - Confederate forces pull out before U.S. advance |
| July 3 | Pony Express arrives in San Francisco with overland letters from New York |
| July 4 | In a special session of 27th Congress Lincoln requests 400,000 troops |
| July 4 | Skirmish at Harper's Ferry, West Virginia |
| July 5 | Battle of Carthage, Missouri - U.S. General Sigel attacks pro-secessionist |
| July 7 | Battle of Laurel Hill, Virginia |
| July 8 | CS General Sibley is given command of rebel troops in New Mexico territory |
| July 10 | Lincoln writes to Kentucky's militia and says Union troops will not enter that state |
| July 11 | Battle of Laurel Mountain Virginia - General Morris forces retreat of rebels |
| July 11 | Battle of Rich Mountain, Virginia - Rosecrans forces rebels to surrender |
| July 13 | Battle of Corrick's Ford, Virginia (Carrick's Ford) - Union army takes total control of western Virginia CS20 US53 |
| July 14 | General McDowell advances toward Fairfax Courthouse, Virginia with 40,000 troops |
| July 14 | Naval Engagement at Wilmington North Carolina - USS Daylight establishes blockade |
| July 16 | Battle of Bull Run, the 1st major battle of the Civil War, is fought |
| July 17 | Congress authorizes paper money |
| July 17 | Manassas, Virginia General Beauregard requests reinforcements for his 22,000 men, General Johnston is ordered to Manassas |
| July 18 | Battle of Blackburn's Ford, Virginia US57 CS68 - Manassas - |
| July 20 | Confederate state's congress began holding sessions in Richmond, Virginia |
| July 21 | 1st major battle of Civil War ends (Bull Run), Va-South wins |
| July 24 | Skirmish at Taylor Mountain, (W)Virginia - CS General Wise retreats |
| July 25 | Skirmish at Fort Fillmore, New Mexico Terr - Rebels attack Union troops |
| July 25 | Washington D.C. - Crittenden resolution is passed stating that the war is to be fought to preserve union and uphold the Constitution, not to alter slavery |
| July 27 | Battle of Mathias Point, Virginia - Rebel forces repel a Federal landing |
| July 27 | Battle of St. Augustine Springs, New Mexico Terr |
| July 27 | Confederate troops occupy Fort Fillmore, New Mexico |
| July 27 | Union General George McClellan takes command from McDowell of Potamic Army |
| July 31 | 9,300 mm rainfall in July in Cherrapunji, Assam: world record |
| August 1 | Brazil recognizes Confederacy |
| August 3 | Federal fleet bombs Galveston, Texas |
| August 5 | Enlistment increases from 3 months to 2 years |
| August 5 | Naval Engagement at Fernandina, FL-USS Vincennes ends rebel blockade |
| August 5 | U.S. Army abolishes flogging |
| August 5 | U.S. levies its 1st Income Tax (3% of incomes over $800) |
| August 6 | Lexington Kentucky - Union military camp forms in neutral state |
| August 10 | Battle of Wilson's Creek MO (Springfield, Oak Hills)-General Lyon killed |
| August 12 | Skirmish at Texas-rebels are attacked by Apache Indians |
| August 14 | 79th New York troops mutinies |
| August 16 | President Lincoln prohibits Union states from trading with Confederacy |
| August 16 | Skirmishes at Fredericktown/Kirkville, Missouri |
| August 27 | Battle of Cape Hatteras SC-Union troops take Ft. Clark |
| August 28 | Battle of Fort Hatteras NC |
| September 1 | Grant assumes command of Federal forces at Cape Girardeau MI |
| September 1 | Skirmish at Boone Court House WV and Blue Creek WV |
| September 3 | Confederate forces enter Kentucky, thus ending its neutrality |
| September 6 | General Grant occupies Paducah Kentucky |
| September 9 | Sally Tompkins is only Confederate Army female commissioned officer |
| September 10 | Battle at Cheat Mountain, Elkwater West Virginia |
| September 10 | Battle of Carnifex Ferry VA, 170 casualities |
| September 13 | 1st naval battle of Civil War, Union frigate "Colorado" sinks privateer "Judah" off Pensacola, Fla |
| September 16 | British Post Office Savings Banks opens |
| September 17 | 1st day school for freedmen forms at Fortress Monroe Virginia |
| September 17 | Hampton Institute forms |
| September 20 | Battle of Lexington, MI-captured by Union |
| September 25 | Secretary of U.S. Navy authorizes enlistment of slaves |
| September 26 | 2nd British Golf Open: Tom Morris Sr shoots a 163 at Prestwick Club |
| October 2 | Former Vice President John C. Breckinridge flees Kentucky |
| October 6 | Naval Engagement at Charleston, South Carolina USS Flag vs BR Alert |
| October 6 | Revolt of Russian student shuts down university of Petersburg |
| October 11 | Battle of Dumfries, Virginia (Quantico Creek) |
| October 12 | Confederate ironclad Manassas attack Union's Richmond on Mississippi |
| October 16 | Confederacy starts selling postage stamps |
| October 21 | Battle of Balls Bluff, Virginia (Leesburg, Harrison's Island) |
| October 22 | 1st telegraph line linking West and East coasts completed |
| October 24 | 1st transcontinental telegram sent ending Pony Express |
| October 24 | West Virginia seceded from Virginia |
| October 25 | Battle of Wilson's Creek, MI (Springfield) |
| October 26 | Pony Express ends |
| November 1 | General George B. McClellan made general in chief of Union armies |
| November 4 | University of Washington founded in Seattle |
| November 6 | Jefferson Davis elected to 6 year term as Confederate president |
| November 7 | Battle of Belmont, MO |
| November 7 | Battle of Port Royal Bay, South Carolina (Ft. Walker, Ft. Beauregard) |
| November 8 | Battle of Mount Ivy, Kentucky |
| November 8 | U.S. removes Confederate officials from British steamer Trent |
| November 9 | 1st documented Canadian football game (at University of Toronto) |
| November 19 | Julia Ward Howe committed "Battle Hymn of the Republic" to paper |
| November 22 | Battle of Ft. McRee, FL |
| November 24 | Luik-Vise-Maastricht railway opens |
| November 26 | West Virginia created as a result of dispute over slavery with Virg |
| November 28 | Confederate congress officially admits Missouri to Confederate Army |
| November 30 | Harper's Weekly publishes EE Beers' "All quiet along the Potomac" |
| December 5 | Gatling gun patented |
| December 9 | Battle of Bird Creek, Indian Terr (High Shoal, Chusto-Talasah) |
| December 13 | Battle of Alleghany Summit, WV |
| December 19 | Battle of Black Water |
| December 20 | Battle of Dranesville, VA |
| December 30 | US, banks stops payments in gold |
| December 31 | 22,990 mm of rain falls in Cherrapunji Assam in 1861, world record |
