Legal in the United States since 2010, moonshine is defined as "clear, unaged whiskey", typically made with corn mash as its main ingredient. Liquor-control laws in the United States always applied to moonshine, with efforts accelerated during the total ban on alcohol production mandated under the 18th Amendment of the Constitution. Since its repeal, and moonshine's recent legalization, they focus on evasion of revenue taxation on spiritous or intoxicating liquors. Applicable laws are enforced by the Bureau of Alcohol, Tobacco, Firearms and Explosives of the US Department of Justice, once known colloquially as "revenooers".
Moonshine is known by many nicknames, including white liquor, white lightning, mountain dew, choop, hooch, homebrew, white whiskey, and mash liquor.
The word "moonshine" is believed to be derived from the term "moonrakers" used for early English smugglers and the clandestine nature of the operations of the illegal Appalachian distillers who produced and distributed whiskey.
When illegal in the United States, moonshine distillation was done at night to avoid discovery. Moonshine was especially important to the Appalachian area. This white whiskey most likely entered the Appalachian region in the late 18th century to early 1800s. Scots-Irish immigrants from the province of Ulster in the north of Ireland brought their recipe for uisce beatha, Gaelic for "water of life". The settlers made their whiskey without aging it, and this is the same recipe that became traditional in the Appalachian area.
In the early 20th century, moonshine became a key source of income for many Appalachian residents like Marvin "Popcorn" Sutton, since the limited road network made it difficult and expensive to transport corn crops. As a study of farmers in Cocke County, Tennessee, observes: "One could transport much more value in corn if it was first converted to whiskey. One horse could haul ten times more value on its back in whiskey than in corn." Moonshiners in Harlan County, Kentucky, like Maggie Bailey, made the whiskey to sell in order to provide for their families. Others, like Amos Owens, from Rutherford County, North Carolina and "Popcorn" Sutton from Maggie Valley, North Carolina sold moonshine to nearby areas.