This article lists battles and campaigns where the number of U.S. soldiers killed was higher than 1,000. The battles and campaigns that reached that number of deaths in the field are so far limited to the American Civil War, World War I, World War II, Korean War and one campaign during the Vietnam War. The campaign that resulted in the most U.S. military deaths was the Battle of Normandy where 29,204 soldiers were killed fighting against the German Reich. The bloodiest single–day battle in American history was the Battle of Antietam when 22,654 Union and Confederate soldiers were killed or wounded on September 17, 1862. However, for the United States military specifically, the bloodiest single day is June 6, 1944 with 2,500 soldiers killed during the Invasion of Normandy on D-Day. The origins of the United States military can be traced to the Americans' fight for independence from their former colonial power, Great Britain, in the American Revolutionary War. The three bloodiest conflicts have been American Civil War, World War I and World War II. Other significant conflicts involving the United States ordered by casualties include, Korean War, Vietnam War, the War in Afghanistan and various conflicts in the Middle East. For most of its existence, America has been involved in one or another military conflict.
Scope and definitions
The definition of "battle" as a concept in military science has been a dynamic one through the course of military history, changing with the changes in the organization, employment and technology of military forces. From the beginning of history until the 20th century, "battle" has usually meant a military clash over a relatively small area, lasting only a few days at most ; for instance, the Battle of Waterloo, begun, fought, and ended on 18 June 1815 on a field a few kilometers across. Another use of the term "battle", seen particularly in the 20th century, is as equivalent to military campaign ; for instance the Battle of the Atlantic, fought over several years in an area constituting about twenty percent of the Earth's surface. Since these two types of "battles" aren't usefully comparable in many ways, this article is divided into two sections, one for battle in the older, more restricted sense, and one for campaigns, many of which are also called battles. There are actions at the margins that could be reasonably assigned to either list. For instance, the Battle of Spotsylvania lasted 14 days, but the main part was fought on a small field, and in this way being more in the nature of a siege. Like the similar Battle of Cold Harbor, also part of the Overland Campaign, it is included in this article on the Battles list. The Battle of Saint-Mihiel is also included on the Battles list. The term casualty in warfare can often be confusing. It often does not refer to those that are killed on the battlefield; rather, it refers to those who can no longer fight. This 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 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. In this article the numbers killed refer to those killed in action, killed by disease or someone who died from their wounds.
