The Coinage Act of 1792 was entered into law on April 2. It proclaimed the creation of the United States Mint. Philadelphia at that time was the nation's capital; therefore the first mint facility was built there. The Mint Act also instituted a decimal system based on a dollar unit; specified weights, metallic composition and fineness; and required each United States coin feature "an impression emblematic of liberty".
Two blocks from the site of the first mint, the fourth and current Philadelphia Mint opened its doors in 1969. It was designed by Philadelphia architect Vincent G. Kling, who would also help design Five Penn Center, Centre Square, and the Annenberg Center for the Performing Arts. It was the world's largest mint when it was built and held that distinction as of October 2017.
The Philadelphia Mint can produce up to one million coins in 30 minutes. It took three years for the original mint to produce that many. The mint also produces medals and awards for military, governmental, and civil services. Engraving of all dies and strikers only occurs here. Uncirculated coins minted here have the "P" mint mark, while circulated coins from before 1980 carried no mint mark except the Jefferson nickels minted from 1942–1945 and the 1979 Susan B. Anthony dollar coins. Since 1980, all coins minted there have the "P" mint mark except cents until 2017.
Tours can be taken where all stages of minting are explained, along with displays of past equipment. This takes place via an enclosed catwalk above the minting facility itself. Various video stations are placed along the tour route, where visitors can push buttons to watch videos about various stages of the minting process. Most of those videos were narrated by Baseball Hall of Fame announcer for the Philadelphia Phillies (and voice of NFL Films), Harry Kalas.
According to wikipedia
