The story behind the coin
In 1926, Philadelphia threw a party for the country's 150th birthday. The Sesquicentennial International Exposition — "sesquicentennial" simply means a 150th anniversary — sprawled across South Philadelphia to mark a century and a half since the Declaration of Independence was signed a few miles away. Like most expositions of the age, it needed money, and Congress had a familiar tool to raise it.
By an act of March 3, 1925, Congress authorized two commemorative coins to help fund the fair: up to one million silver half dollars and 200,000 gold quarter eagles ($2.50 pieces). The organizers could buy them from the Mint at face value and resell them at a premium — the half dollar went out at $1, double its spending power. The profit was meant to flow back to the exposition.
It did not go as planned. The fair drew millions of visitors but ran a deep deficit, and the coins sold badly. Of the roughly one million half dollars struck at the Philadelphia Mint in May and June 1926, the great majority came back unsold. The Mint melted 859,408 of them. What survived — about 141,120 coins — is the entire population that exists today.