Of the many famous images and terms from the Vietnam era, Agent Orange is one of the most memorable.

Agent Orange was a codename for a herbicide used to defoliate trees and shrubs that provided cover for enemy troops. The name derived from the orange bands used to mark its storage drums. Although the United States military used other defoliants such as Agents White, Blue, and Purple, Agent Orange was the most widely used due to its proven effectiveness against broad-leaf jungle plants in Southeast Asia.

Agent Orange consisted of two equally mixed chemicals. This mixture was then combined with kerosene or diesel fuel to create a potent herbicide, the active ingredients of which acted like a plant growth hormone to disrupt the plants' normal functions. During "Operation Ranch Hand," the US Army sprayed approximately eleven million gallons of Agent Orange over six million acres of Vietnamese land.

Near the end of the war, Agent Orange was found to contain dioxin, a highly toxic byproduct of the chemical manufacturing process. This discovery led many scientists to believe that the dioxin content of Agent Orange was responsible for serious diseases suffered by Vietnam Veterans and the Vietnamese people.

Recent and ongoing studies have established associative links between exposure to Agent Orange and various forms of cancer and diabetes. Although fewer studies have been conducted on the long-term effects of Agent Orange exposure for the Vietnamese, scientists have suggested links between Agent Orange contamination and severe birth defects.