The Deadliest Battles in the Civil War

Updated January 25, 2022 | Infoplease Staff

America's costliest war

The Civil War led to  the greatest loss of life in American history. Over the course of the entire war, including USA and CSA casualties, some 620,000 people were killed in the war, equaling roughly 2% of the American population. Many more were injured or displaced by the economic turmoil. Estimates from the 2010s put the total death count at upwards of 800,000; at the most generous figure, one in 30 Americans died as part of the conflict.

"Casualty" vs. "Fatality"

The term casualty is often misconstrued to mean people who died due to an armed conflict or state action. A casualty refers to anyone rendered incapable of active service, not just the deceased. Someone who is too injured to return to regular duty is also a casualty. We have decided to rank battles by fatalities rather than casualties.

Gettysburg was the bloodiest battle of the Civil War, with more than 51,000 casualties, including 7,863 dead. If we count US and CS casualties, it is the deadliest battle in American history (even ahead of D-Day). The deadliest single-day battle was at Antietam. Battle deaths in the Civil War totaled nearly 215,000. Below is a list of the deadliest battles in the war.

Battle Dates Number of fatalities
Battle of Gettysburg June 3, - July 24, 1863 7,863 (3,155 Union troops; and 4,708 Confederate)
Battle of Spotsylvania Court House May 8 - 21, 1864 4,192 (2,725 Union troops; and 1,467 Confederate)
Battle of Chickamauga Sep. 1 - 20, 1863 3,969 killed (1,657 Union troops; 2,312 Confederate)
Battle of the Wilderness May 5 - 7, 1864 3,723 (2,246 Union troops; 1,477 Confederate)
Antietam Campaign Sep. 17, 1862 3,650 (2,100 Union troops; 1,550 Confederate)
Battle of Shiloh April 6 - 7, 1862 3,482 (1,754 Union troops; and 1,728 Confederate)
Battle of Chancellorsville April 30 - May 6, 1863 3,271 (1,606 Union troops; and 1,665 Confederate)
Second Battle of Bull Run (Second Manassas) August 29 - 30, 1862 3,205 killed (1,724 Union troops; 1,481 Confederate)
Battle of Stone's River Dec. 31, 1862 - Jan. 2, 1863 2,971 (1,677 Union troops; and 1,294 Confederate)
Battle of Fredericksburg December 11 - 15, 1862 1,892 (1,284 Union troops; and 608 Confederate)

See also Post-Vietnam Combat Casualties.

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Sources +

Department of Defense and Veterans Administration, the National Park Service