The Cambodian genocide

The genocide triggered a second outflow of refugees, many of whom escaped to neighboring Thailand and, to a lesser extent, Vietnam. The Vietnamese invasion of Cambodia ended the genocide by defeating the Khmer Rouge in January 1979. In 2001, the Cambodian government established the Khmer Rouge Tribunal to try the members of the Khmer Rouge leadership responsible for the Cambodian genocide. Trials began in 2009, and in 2014, Nuon Chea and Khieu Samphan were convicted and received life sentences for crimes against humanity committed during the genocide.

Carbine: A breech-loading, single-shot, rifle-barreled gun primarily used by cavalry troops. A carbine's barrel is several inches shorter than a regular rifle-musket.

Flank: Used as a noun, a "flank" is the end (or side) of a military position, also called a "wing". An unprotected flank is "in the air", while a protected flank is a "refused flank". Used as a verb, "to flank" is to move around and gain the side of an enemy position, avoiding a frontal assault.

Campaign: A series of military operations that form a distinct phase of the War (such as the Shenandoah Valley Campaign).

Volunteer: Someone who does something because they want to, not because they need to. Most Civil War soldiers, especially in the beginning of the War, were volunteers. Men joined the armies on both sides because they wanted to fight for their cause.

Bummer: A term used to describe marauding or foraging soldiers. Although armies on both sides often had rules against foraging or stealing from private residences, some soldiers often found ways to do so.