gallon

The gallon is a unit of liquid and dry measure used in the British Imperial and United States Customary systems. In the U.S., a liquid gallon is defined as 231 cubic inches or four quarts. The British Imperial gallon is larger, equivalent to 4.546 liters, while the U.S. liquid gallon is 3.785 liters. Historically, the size of a gallon varied depending on the liquid being measured, such as wine, ale, or beer, and was often based on the size of actual wooden barrels. The U.S. gallon is derived from the Queen Anne wine gallon, which was adopted after the British Imperial System standardized its gallon in 1824.1234