Tradition tells of how Thomas J. Smith of London
invented crackers in 1847. He created the crackers
as a development of his bon-bon sweets, which he
sold in a twist of paper (the origins of the traditional
sweet-wrapper). Smith added the "'crackle' element
when he heard the crackle of a log he had just put on
a fire. The new product was initially marketed as
the Cosaque (i.e., Cossack), but the onomatopoeic
'cracker' soon became the commonly used name.
However, the OED may well be in error as they
appear to have been available in France in 1817.
Images: Front covers of Tom Smiths
1903/1904 and 1906/1907 catalogues