Way back in the
1960s the
Americans decided they
needed a system to provide
code numbers for
all products so that
bar codes could be
implemented. Thus the 12-digit
UPC was born and duly titled
to be
universal so as to connote its
universality.
Not too long after that,
the rest of the world
desired a similar system but found that the UPC system
lacked sufficient digits for
the word (let alone the universe).
Thus was born 13-digit
WPC.
Sources: http://www.barcodingsolutionsinc.com/bar_code_history.html