Bloodiest battles

Shiloh

Period: Apr 6, 1862 to Apr 7, 1862

Union won
Union- 13,047
Confederate- 10,669
Tennessee

Second Manassas

Period: Aug 28, 1862 to Aug 30, 1862

Confederate won
Union- 13,824
Confederate- 55,000
Virginia

Antietam

Period: Sep 16, 1862 to Sep 18, 1862

Inconclusive
Union- 12,401
Confederate- 10,316
Maryland

Stones River

Period: Dec 31, 1862 to Jan 2, 1863

Union won
Union- 12,906
Confederate- 11,739
Tennessee

Chancellorsville

Period: Apr 30, 1863 to May 6, 1863

Confederate won
Union- 17,304
Confederate- 13,460
Virginia

Vicksburg

Period: May 18, 1863 to Jul 4, 1863

Union won
Union- 4,910 Confederate- 32,363
Mississippi

Gettysburg

Period: Jul 1, 1863 to Jul 3, 1863

Union won
Union- 23,049
Confederate- 28,063
Pennsylvania

Chickamauga

Period: Sep 18, 1863 to Sep 20, 1863

Confederate won
Union-16,170
Confederate- 18,454
Georgia

The Wilderness

Period: May 5, 1864 to May 7, 1864

Inconclusive
Union- 18,400
Confederate- 11,400
Virginia

Spotsylvania Court House

Period: May 8, 1864 to May 21, 1864

Inconclusive
Union-18,000
Confederate- 12,000
Virginia