# American units with the highest percentage of casualties per conflict

This short description is INTENTIONALLY "none" &#x2D; please see WP:SDNONE before you consider changing it! During warfare, some units take more casualties than other units. Sometimes, the casualty rate is disproportionately high. This article displays the highest percentage of casualties among American units, including those wiped out as an effective force.
The term casualty in warfare can often be confusing. It often refers not to those that are killed on the battlefield but to those who can no longer fight. That can include disabled by injuries, disabled by psychological trauma, captured, deserted, or missing. A casualty is just a soldier who is no longer available for the immediate battle or campaign, the major consideration in combat. The number of casualties is simply the number of members of a unit who are not available for duty. For example, during the Seven Days Battles in the American Civil War (June 25 to July 1, 1862) there were 5,228 killed, 23,824 wounded and 7,007 missing or taken prisoner for a total of 36,059 casualties. The word casualty has been used in a military context since at least 1513.

## Battles

| Unit | Conflict | Deployment | Unit size | KIA | WIA | MIA | POW | Total | Casualty rate (%) | Opposing force | Fate |
| 2nd Infantry Regiment | St. Clair's defeat | November 4, 1791 (1 day of combat) | 900 | 632 | 264 | | | 896 | 99.56 | Northwestern Confederacy inclu. Cherokee, Delaware and others | Unit effectively destroyed, later replenished. A House of Representatives investigation was carried out to investigate the disaster, being the first Congressional Special Committee investigation. |
| 1st Minnesota Infantry Regiment | Battle of Gettysburg, second day | July 2, 1863 | 262 | | | 0 | 0 | 215 | 82 | Confederacy | Survivors reinforced by remaining companies of the regiment. Captured the 28th Virginia Colors at Picketts Charge the next day. Continued to serve in the Army of the Potomac until completion of enlistment on April 29, 1864. Majority of veterans formed the core of the new 1st Minnesota Volunteer Infantry Battalion. |
| 7th Cavalry Regiment | Battle of the Little Bighorn | June 25–26, 1876 | 700~ | 268 | 59 | 0 | 0 | 327 | 45~ | Combined Native American Army Arapaho tribe Cheyenne tribe Lakota tribes | Unit effectively destroyed as a fighting force on 26 June 1876. Later replenished |
| 4th Marine Regiment | Battle of Corregidor | May 5–6, 1942 (2 days of combat) | ~4,000 | 315 | 357 | 15 | 1,388 | ~4,000 | Nearly Total | Japan | 4th Marine Regiment was destroyed only a few surviving Marines and personnel made up what was left of the regiment. The regiment was dissolved by Gen. Wainwright by his own will. Unit re-established in February 1944. |
| 36th Infantry Division | Attack across the Gari River | January 22–24, 1944 (2 days of combat) | 6,000 | 143 | 663 | 875 | | 1,681 | 28.01 | Germany | 141st and 143rd Infantry Regiments destroyed as a fighting force. US Congress investigation to establish responsibility for the disaster in 1946. |
| 1st, 3rd and 4th Ranger Battalion | Battle of Cisterna | January 30, 1944 (1 day of combat) | 767 | 311 | | | 450 | 761 | 99 | Germany | 1st, 3rd and 4th Ranger Battalions destroyed.1st Ranger Battalion reconstituted on 1 September 1948.3rd Ranger Battalion redesignated on 21 June 1954. 4th Ranger Battalion disbanded. |
| 1st Marine Regiment | Battle of Peleliu | September 15–21, 1944 (7 days of combat) | ~3,000 | | | | | 1,749 | 58 | Japan | Regiment relieved from combat, ineffective as a fighting force but not broken. |
| 28th Infantry Division | Battle of Hürtgen Forest | September 19, 1944 | 16,266 | | | | | 6,184 | 38.01 | Germany | 28th Infantry Division destroyed as a fighting force. Unit withdrawn for action. Later replentished. |
| 2nd Infantry Division | Battle of the Ch'ongch'on River | November 26–30, 1950 (4 days of combat) | ~14,000 | | | | | 4,163 | 30 | China North Korea | Major General Laurence B. Keiser commander of 2nd Infantry Division was relieved from command by the end of the battle. |

## US units with most casualties per conflict

| Unit | Conflict | Deployment | Unit size | KIA | WIA | MIA | POW | Total | Casualty rate (%) | Opposing force |
| 1st Minnesota Volunteer Infantry | American Civil War | Apr 29, 1861 - Apr 28, 1864 | | 286 | 609 | | | 895 | | Confederacy |
| 1st Infantry Division (United States) | World War I | October 23, 1917 - Nov 11, 1918 | | 4,964 | 17,201 | 1,056 | | 23,221 | | German Empire |
| Harlem Hellfighters | World War I | Apr 8 - Nov 11, 1918 (191 days at the front) | 3,832 | | | | | 1500 | 40~ | German Empire |
| 3rd Infantry Division | World War II | Nov 8, 1942-May 8, 1945 (553 days of combat) | 6,000 | 4,922 | 18,766 | 554 | 1735 | 25,977 | | Germany Vichy France Italian Social Republic 1943–1945  Kingdom of Italy 1942–1943 |
| 1st Marine Division | Korean War | 1950-1953 | | 4,004 | 25,864 | | | 29,868 | | China North Korea |
| 1st Cavalry Division | Vietnam War | Aug 1965 - Aug 1972 | | 5,444 | 26,592 | | | 32,036 | | North Vietnam Viet Cong |
| 14th Quartermaster Detachment | Gulf War | 1990-1991 | 69 | 13 | 43 | 0 | 0 | 56 | 81.0 | Iraq |
| 3rd Battalion, 5th Marines | War in Afghanistan | 2001-2011 | 950 | 25 | 150 | | | 175 | 18.4 | Taliban |