Ten Biggest Battles of the American Civil War

The largest battles of the civil war where approximately the same size as Waterloo (about 200,000), but that doesn’t even make it into the top ten European  battles of the century. The major clashes of the Napoleonic wars and the Franco-Prussian war were all significantly larger than any battle in the American Civil war. The battle of  Sadowa (Königgrätz)  for instance, the decisive engagement of the Austro-Prussian war fought less than a year after the Civil War had 430,000 combatants; that makes it bigger than the Seven Days and Chancellorsville put together. The conflict’s best known battle, Gettysburg, had 170,000 combatants and so was the same size as Austerlitz – although Gettysburg lasted longer, three days whereas Bonaparte needed only eight hours to annihilate Kutuzov in 1805.

Ten Biggest Battles of the Civil War

Location Year Troops Loss % Result
The Seven Days, VA 1862 196,000 18.4% CS Victory
Chancellorsville, VA 1863 195,000 15.5% CS Victory
Fredericksburg, VA 1862 188,000 9.5% CS Victory
Cold Harbor, VA 1864 167,000 10.4% CS Victory
Gettysburg, PA 1863 166,000 27.7% US Victory
Wilderness, VA 1864 163,000 17.6% Draw
Spotsylvania CH, VA 1864 152,000 20.9% Draw
Chickamauga, GA 1863 130,000 27.2% CS Victory
Sharpsburg, MD 1862 114,000 19.9% Draw
2nd Manassas, VA 1862 112,000 16.3% CS Victory

Ive classified the battles by the total number of combatants, and while this is a reasonable enough guide, it can sometimes be misleading. For instance the Siege of Corinth, Mississippi in 1862 had 185,000 combatants, which would have made it fourth on this list, but the majority of these never fired a shot and consequently the casualties were very small (about 1,000 on each side). Ive only included battles were the majority of the forces deployed were actually engaged. Therefore battles like Resaca, Georgia in 1864 and Yorktown, Virginia in 1862 which would have been seventh and eighth on this list, and 3rd Petersburg (tenth) have also been excluded.

Ten Bloodiest Battles by Attrition Rate

Battle Year Combatants Attrition % Outcome
2nd Murfreesboro (Stones River), TN 1863



US Victory
Gettysburg, PA 1863



US Victory
Chickamauga, GA 1863



CS Victory
Shiloh, TN 1862



US Victory
Spotsylvania Courthouse, VA 1864



US Victory
Perryville, KY 1862



CS Victory
Fort Steadman, VA 1865



US Victory
Sharpsburg (Antietam), MD 1862



Wilderness, Virginia 1864



3rd Winchester (Opequon), VA 1864



US Victory

This table shows the ten costliest battles by attrition rate, that is total casualties / total combatants. Ive excluded sieges and other battles where there were instances of mass surrender, ie where most of the “casulaties” were POW’s. Therefore Grant’s victories at Fort Donaldson and Vicksburg, and Stonewall’s capture of Harper’s Ferry are all excluded. On this measure, Rosecran’s victory over Bragg at 2nd Murfreesboro was the costliest battle on this measure, with nearly a third of those engaged as casualties; with Gettysburg and Chickamauga not far behind.

Copyright ©2012 Savereo John