Until 1980 , coins minted at Philadelphia bore no mint mark , with the exceptions of the Susan B. Anthony dollar and the wartime Jefferson nickel .
The first was built in 1792 , when Philadelphia was still the U.S. capital , and began operation in 1793 .
Until 1980 , coins minted at capital bore no mint mark , with the exceptions of the Susan B. Anthony dollar and the wartime Jefferson nickel .
The first was built in 1792 , when Philadelphia was still the U.S. capital , and began operation in 1793 .