DOLLAR SIGN. Popular belief often ascribes the origin of the dollar sign ($) to a mark on government mail-bags standing for U.S., or Uncle Sam. Another common story claims that the symbol represents the pillars of Hercules on the Spanish dollar. A third explanation for its origin identifies it as a conversion of the old Spanish symbol for the Spanish dollar. Most probably, however, the dollar sign is a conventionalized combination of the letters p and s for pesos. As early as 1788, a government clerk used such a mark, and the present symbol came into general use shortly after that time.