The U.S. Mint Coins:
The original U.S. Mint was constructed in Philadelphia, which was then the nation's capital, in 1792. It was the first Federal building erected under the authorization of the United States Constitution. The Mint in its early days was beset by a lack of reliable equipment and qualified craftsmen, as well as political enemies in Congress. It took three years of operators working manual coin presses 11 hours a day, six days a week, before total production reached one million coins. Compare this to the present facility, which can produce that one million coins in a half hour. The original 1792 coining press can still be seen in the Visitors Gallery at the Philadelphia Mint.
Philadelphia still produces the master coin and medal dies for all U.S. Mint branches. The major focus of the Philadelphia Mint throughout its history has been the production of circulating coins for the United States. It also produced circulating and commemorative coins for many nations between 1833 and 1984, until domestic production grew so large it took up all capacity.
As the United States’ main Mint, Philadelphia did not use a mint mark to distinguish coins struck there until 1942 through 1945, when the silver “war nickels” of WWII were designed with a large "P" mint mark over Monticello on the reverse to distinguish them from the base metal nickels. The “P” mint mark was not used again until 1979.
The Philadelphia Mint is open for self-guided tours Monday through Friday.