The US dry gallon is a unit of volume in the US customary unit system with the symbol dry gal.
The dry gallon is equal to 268.8025 in³ or 4.404 L.
The US dry gallon is not used anywhere any more - the unit below is the dry pint and the unit above is the bushel.
The bushel is a unit of volume in the imperial unit system with the symbol bsh.
1 bushel is equal to 8 dry gallons, or 36.36872 litres.
The bushel was introduced in England as a unit to bridge the relatively large gap between a pound and a ton - and was used largely to measure volumes of liquid being imported and exported following the Norman Conquest such as wine and ale.
The name bushel comes from the ancient French 'boissiel' which means 'little box'.