1861

• January 1
  • Benito Juárez captures Mexico City.
  • First steam-powered carousel recorded, in Bolton, England.
• January 2 – Friedrich Wilhelm IV of Prussia dies and is succeeded by Wilhelm I.
• January 3 – American Civil War: Delaware votes not to secede from the Union.
• January 9 – American Civil War: Mississippi becomes the second state to secede from the Union.
• January 10 – American Civil War: Florida secedes from the Union.
• January 11 – American Civil War: Alabama secedes from the Union.
• January 12 – American Civil War: Major Robert Anderson sends dispatches to Washington.
• January 19 – American Civil War: Georgia secedes from the Union.
• January 21 – American Civil War: Jefferson Davis resigns from the United States Senate.
• January 26 – American Civil War: Louisiana secedes from the Union.
• January 29 – Kansas is admitted as the 34th U.S. state.
• February 1 – American Civil War: Texas secedes from the Union.
• February 4 – American Civil War: In Montgomery, Alabama, the Provisional Confederate States Congress is formed by representatives from the first six break-away states.
• February 8 – American Civil War: The Confederate States of America are formed, comprising the first six break-away States.
• February 9 – American Civil War: Jefferson Davis is elected the Provisional President of the Confederate States of America by the Weed Convention at Montgomery, Alabama.
• February 11
  • American Civil War: The U.S. House unanimously passes a resolution guaranteeing non-interference with slavery in any state.
  • About 850 convicts at Chatham Dockyard in England take over their prison in a riot.
• February 13 – Italian unification: The Siege of Gaeta, stronghold of the Neapolitan King Francis II, is ended by Piedmontese forces. Francis goes into exile.
• February 18 – American Civil War: In Montgomery, Alabama, Jefferson Davis is inaugurated as the provisional president of the Confederate States of America.
• February 20 – In Britain, storms damage the Crystal Palace and cause the collapse of the steeple of Chichester Cathedral.
• February 23 – President-elect Abraham Lincoln arrives secretly in Washington, D.C. after an assassination attempt in Baltimore.
• February 24 – Battle of Ky Hoa: the French and the Spanish defeat the Vietnamese.
• February 27 – Russian troops fire upon a crowd in Warsaw protesting Russian rule over Poland, killing 5 protesters.
• February 28 – Colorado is organized as a United States territory.
• March 2
  • Nevada is organized as a United States territory.
  • American Civil War: Texas is admitted to the Confederate States of America.
• March 3 (February 19 O.S.) – Emancipation reform of 1861: Serfdom is abolished in the Russian Empire.
• March 4
  • President Abraham Lincoln takes office, succeeding James Buchanan.
  • American Civil War: The "Stars and Bars" is adopted as the flag of the Confederate States of America.
• March 10 – El Hadj Umar Tall seizes the city of Ségou, destroying the Bamana Empire of Mali.
• March 11 – American Civil War: The Constitution of the Confederate States of America is adopted.
• March 13 – Tsushima incident: the Russian corvette Posadnik arrives at Tsushima Island in the Korea Strait, Japan, provoking a reaction from the Japanese Shogunate.
• March 17 – Italian unification: The Kingdom of Italy is proclaimed by the new Parliament, with Victor Emmanuel II of Piedmont-Sardinia becoming its king.
• March 19 – The First Taranaki War ends in New Zealand.
• March 20
  • An earthquake completely destroys Mendoza, Argentina.
  • Italian unification: The surrender of Civitella del Tronto ends the Kingdom of the Two Sicilies.
• March 21 – Alexander Stephens, Vice President of the Confederacy, gives the infamous Cornerstone Speech in Savannah, Georgia, in which he declares that slavery is the natural condition of blacks and the foundation of the Confederacy.
• March 28 – Confederate Arizona: convention in present-day Tucson ratified the ordinance of secession of southern part of New Mexico Territory.
• March 30 – Discovery of the chemical elements: Sir William Crookes announces his discovery of thallium.

Im Jahr 1861 wendet sich die weltpolitische Aufmerksamkeit dem amerikanischen Kontinent zu: Nach der Wahl von Abraham Lincoln zum Präsidenten der Vereinigten Staaten im November des Vorjahres erklären Anfang des Jahres mehrere Südstaaten ihren Austritt aus der Union und gründen wenig später die Konföderierten Staaten von Amerika. Jefferson Davis wird zum Präsidenten der Konföderation gewählt. Mit dem Angriff auf Fort Sumter beginnt am 12. April schließlich der Amerikanische Bürgerkrieg, bei dem beide Seiten noch mit einem baldigen Ende innerhalb eines Jahres rechnen.

1861 (MDCCCLXI) fue un Año normal comenzado en martes según el calendario gregoriano.

Het jaar 1861 is het 61e jaar in de 19e eeuw volgens de christelijke jaartelling.