Historical eventSeptember 171862

American Civil War

American Civil War: Almost 23,000 total casualties were suffered at the Battle of Antietam near Sharpsburg, Maryland, where Confederate and Union troops fought to a tactical stalemate.

Everything on September 17Original source

In context

When
Wednesday, September 17 1862164 years ago
Category
Historical eventA dated happening — a battle, treaty, launch, discovery, disaster or decision — recorded on this calendar day.
Era
19th century · 1860s
Recorded from
Wikipedia “On this day” feed

Russia, Greece and some other countries used the Julian calendar into the early 20th century, so local records may show a date up to 13 days earlier.

At a glance

Dates: From 1862.

What came beforeAI-assisted

Tensions over slavery's expansion into western territories had divided North and South for decades. The Missouri Compromise (1820), Compromise of 1850, and Kansas-Nebraska Act (1854) temporarily eased conflicts but ultimately deepened sectional rifts.

Abraham Lincoln's election in November 1861 on a platform opposing slavery's expansion prompted eleven Southern states to secede and form the Confederate States of America in February 1861.

Catalyst / how it startedAI-assisted

Confederate forces fired on Fort Sumter in Charleston Harbor on April 12, 1861, after the Union refused to evacuate the federal installation. Lincoln called for 75,000 volunteers to suppress the rebellion, prompting four more states to join the Confederacy.

Who was involvedAI-assisted

The Union was led by President Abraham Lincoln and commanded militarily by generals including Ulysses S. Grant and William Tecumseh Sherman. The Confederacy was led by President Jefferson Davis with generals Robert E. Lee and Braxton Bragg among its commanders.

TimelineAI-assisted

April 12, 1861: Confederate attack on Fort Sumter begins the war. September 17, 1862: Battle of Antietam becomes the bloodiest single day in American military history.

January 1, 1863: Emancipation Proclamation takes effect, freeing enslaved people in Confederate states. April 9, 1865: General Lee surrenders at Appomattox Court House, effectively ending the war.

What happened

The American Civil War was a civil war in the United States between the Union and the Confederacy, which was formed in 1861 by states that had seceded from the Union to preserve slavery in the United States. The South saw slavery as threatened because of the election of Abraham Lincoln and the growing abolitionist movement in the North. The war ended with Union victory, the dissolution of the Confederacy and the abolition of slavery, freeing four million African Americans.

September 17 through the years

Other entries on the same calendar day, in order.

  1. 1862American Civil War
  2. 2006Őszöd speech
  3. 2006Fourpeaked Mountain
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  6. 2011Occupy Wall Street
  7. 2013Grand Theft Auto V
  8. 20162016 New York and New Jersey bombings
  9. 2018Israeli Air Force
  10. 2018Syria missile strikes (September 2018)
  11. 2025Strategic Mutual Defence Agreement

Also in 1862

  • September 15American Civil WarAmerican Civil War: Confederate forces captured the Union garrison at Harpers Ferry, Virginia, taking more than 12,000 prisoners.
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  • July 17GarroteThe garrotting and robbery of James Pilkington, a British member of Parliament, led to a moral panic in London.
  • January 16Coal miningA pumping engine at a colliery in New Hartley, England, broke and fell down the shaft, trapping miners below and resulting in 204 deaths.
  • December 26American Civil WarAmerican Civil War: The Battle of Chickasaw Bayou began with Confederate defenders engaging Union forces who were attempting to capture t…
  • August 4BrooklynIn Brooklyn, a mob composed largely of Irish Americans attacked a group of African Americans in a riot.
  • December 7American Civil WarAmerican Civil War: The Battle of Prairie Grove ended a Confederate attempt to regain control of northwestern Arkansas.
  • July 1American Civil WarAmerican Civil War: Confederate general Robert E. Lee launched a series of disjointed and ultimately unsuccessful assaults on the nearly…

Everything we record for 1862 →

Sources

Cite this page

“American Civil War”, What's On This Date, https://whatsonthisdate.com/app/event/american-civil-war-1862-september-17, accessed October 27, 2026.

Cite the underlying source as well — the source links above go to the record this entry is adapted from.

Questions about this entry

When did American Civil War happen?

September 17 1862 — 164 years ago, on a Wednesday.

Where does this text come from?

Wikipedia “On this day” feed. Summaries are short adaptations that link back to the source, not reprints. Panels marked AI-assisted were filled where the sources left a heading empty.

How do I cite this page?

Use the ready-made citation near the sources at the bottom of the page, and follow the source link to cite the underlying record as well.

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