The sandwich was invented by an English aristocrat who wanted to eat without putting down his cards.
Why it is true
The Earl of Sandwich, John Montagu, liked to play cards for hours. To avoid interrupting the game to eat, he asked for meat between two slices of bread. The invention was adopted by his friends and the name stuck.
Source: Smithsonian
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.