why is there a long ton and a short ton, where did this come from?

Answer 1

Long Ton (sometimes known as a Gross Ton, Weight Ton, or Imperial Ton) is the name for the unit called the "Ton" in the Avoirdupois or Imperial system of measurements, as formerly used in the United Kingdom and several other Commonwealth countries. It has been replaced by the metric tonne. It is equal to 2240 pounds (exactly 1016.0469088 kilograms).

The standard ton in the U.S. measurement system is the "short ton", equal to 2000 pounds (exactly 907.18474 kg). Both long and short tons are defined as 20 hundredweights, but a hundredweight is 112 pounds (which is equal to 8 stone) in the Imperial system (long or gross hundredweight) and 100 pounds in the US system (short or net hundredweight).