September 17: It's still known as America's bloodiest day

By John Keller

Posted by John Keller

On this date, September 17, more Americans were killed, wounded, or missing than on any other single day in American history -- not on 9/11, not in the Argonne Forest, not even at Pearl Harbor. It was outside of a sleepy little town in Western Maryland called Sharpsburg, along a meandering stream locally known as Antietam Creek.

The year was 1862, and this quiet place -- as relatively unpopulated today as it was then -- was where two great armies of the American Civil War crashed into each other in dawn-to-dusk bloodshed that produced 22,717 casualties on both sides -- 3,650 killed, 17,300 wounded, 1,770 captured or missing -- in an epic fight that ultimately resulted in the Emancipation Proclamation that freed Americans held in slavery.

It was America's bloodiest day.

Why it happened along Antietam Creek was largely an accident. Robert E. Lee's Confederate Army of Northern Virginia, for the first time, was invading the North, largely to relieve Virginia, which had been under prolonged Union attack for more than a year.

Mountains and Rebel cavalry screened Lee's movements from prying federal eyes, and Union commander George Brinton McClellan had no idea where the Confederate army would strike ... until five days before the battle when a Union private from Indiana found in the grass where he was camped a piece of paper wrapped around three cigars.

The brand of cigars and who got to smoke them is lost to history, but the paper containing them turned out to be General Lee's Special Order 191, which detailed the Southern army's entire plan for the invasion. It didn't take long for that lost order to make its way to General McClellan, who managed to get his lumbering blue-clad army moving to intercept the Confederates, on a course for Antietam Creek.

The sun rose that September 17 with the Union and Confederate armies facing each other over terrain that came to have ominous names -- the West Wood, the Cornfield, the Bloody Lane, and the Burnside Bridge. When fighting ended, the Confederate army was still intact, but damaged so severely that General Lee ordered it back across the Potomac and into Virginia, ending the invasion.

The next time these armies would face one another on Union soil would be less than a year later around a small Pennsylvania town called Gettysburg.

Previous Blog Posts

Capital Hill budget deal could restore tens of billions of dollars to the Pentagon

December 17, 2013

Hacker drone story a cautionary tale about the need for unmanned vehicle data security

December 10, 2013

Lack of money for systems upgrades threatens to maintain wind-farm radar dead spots

December 3, 2013

Engineering support contracts indicate the Pentagon is sinking into the Mothball Strategy

November 26, 2013

The revenge of COTS: an ageing commercial technology base complicates military supply chain

November 19, 2013

Navy's newest destroyers evolve to fill traditional battleship roles

November 12, 2013

International suspicions of U.S. encryption technology putting defense companies in a bind

November 5, 2013

Defense industry left guessing as Army struggles forward with an unclear mission

October 29, 2013

These are tough times for the combat vehicle and vetronics industries

October 22, 2013

Is the government shutdown a harbinger of more ominous things to come?

October 15, 2013

Government shutdown reduces military contracting, increasing pressure on U.S. defense industry

October 7, 2013

Potential good news: has U.S. defense spending finally bottomed-out?

October 1, 2013

Is robotics revolution the first glimpse of a fundamental change in human evolution?

September 24, 2013

Obsolescent parts: are we enhancing military readiness or creating a hollow force?

September 17, 2013

For the high-tech warfighter, the future of electronics-laden uniforms is here

September 10, 2013

New generation of embedded computing thermal management in development at GE

September 3, 2013

Trading bus stops for credit cards: how far embedded computing has come in three decades

August 27, 2013

Unmanned vehicle industry stands at the doorstep of a fundamental transformation

August 20, 2013

AUVSI 2013, one of the biggest unmanned vehicles shows in the world, opens this week in Washington

August 13, 2013

The Washington Post, under Jeff Bezos, could lead the way for media in the 21st Century

August 6, 2013

Are costs and vulnerabilities making military leaders nervous about satellite communications?

July 30, 2013

Unmanned aircraft carrier that travels beneath the waves may be in the Navy's future

July 23, 2013

Electronic warfare programs kick into high gear with a flurry of contract activity

July 16, 2013

How vulnerable are U.S. Navy vessels to advanced anti-ship cruise missiles?

July 9, 2013

First came VHSIC, then came MIMIC, and now comes ACE to push electronics technology

July 2, 2013

The Mil & Aero Bloggers

John Keller is editor-in-chief of Military & Aerospace Electronics magazine, which provides extensive coverage and analysis of enabling electronic and optoelectronic technologies in military, space, and commercial aviation applications. A member of the Military & Aerospace Electronics staff since the magazine's founding in 1989, Mr. Keller took over as chief editor in 1995.

Ernesto Burden is the publisher of PennWell’s Aerospace & Defense Media Group, including Military & Aerospace Electronics, Avionics Intelligence and Avionics Europe.  He’s a father of four, a runner, and an avid digital media enthusiast with a deep background in the intersection of media publishing, digital technology, and social media. He can be reached at and on Twitter @aero_ernesto.

Courtney E. Howard, as executive editor, enjoys writing about all things electronics and avionics in PennWell’s burgeoning Aerospace and Defense Group, which encompasses Military & Aerospace Electronics, Avionics Intelligence, the Avionics Europe conference, and much more. She’s also a self-proclaimed social-media maven, mil-aero nerd, and avid avionics geek. Connect with Courtney at, @coho on Twitter, and on LinkedIn.

Mil & Aero Magazine

July 2015
Volume 26, Issue 7

All Access Sponsors

Download Our Apps




Connect with Us


Military & Aerospace Electronics

Weekly newsletter covering technical content, breaking news and product information

Cyber Security

Monthly newsletter covering cyber warfare, cyber security, information warfare, and information security technologies, products, contracts, and procurement opportunities

Defense Executive

Monthly newsletter covering business news and strategic insights for executive managers

Electronic Warfare

Quarterly newsletter covering technologies and applications in electronic warfare, cyber warfare, optical warfare, and spectrum warfare.

Embedded Computing Report

Monthly newsletter covering news on embedded computing in aerospace, defense and industrial-rugged applications

Unmanned Vehicles

Monthly newsletter covering news updates for designers of unmanned vehicles