Stop it ! The US has never used the Imperial system.
The US system is based on the units used in England in the 17th century and has changed very little since, except everything is now defined in terms of metric equivalents.
The Imperial system is based on the units used in England in the 17th century but did not exist until The British Weights and Measures Act of 1824.
There were three different gallon measures commonly used in England prior to 1824, the dry gallon, the wine gallon and the ale gallon. England decided to straighten out some of the nonsense. The Crown decreed that a gallon is equal to the volume displaced by ten pounds of water at 62F (17C). None of this wet/dry nonsense.
Fun fact: 60 mph is 11.4 million barleycorns per hour.
The US system is based on the units used in England in the 17th century and has changed very little since, except everything is now defined in terms of metric equivalents.
The Imperial system is based on the units used in England in the 17th century but did not exist until The British Weights and Measures Act of 1824.
There were three different gallon measures commonly used in England prior to 1824, the dry gallon, the wine gallon and the ale gallon. England decided to straighten out some of the nonsense. The Crown decreed that a gallon is equal to the volume displaced by ten pounds of water at 62F (17C). None of this wet/dry nonsense.
Fun fact: 60 mph is 11.4 million barleycorns per hour.
