Why are letters on keyboards arranged in 'QWERTY' format?

The 'QWERTY' format of letters on most keyboards is taken from typewriters, wherein, an alphabetical ordered keyboard was avoided to stop keys from sticking together. The invention of the 'QWERTY' keyboard is attributed to American inventor Christopher Sholes, who reportedly aimed to slow down typists by arranging the most common letters in 'hard-to-reach' spots.