The Wikipedia article of the day for April 30, 2018 is Louisiana Purchase Exposition dollar.
The Louisiana Purchase Exposition dollar was a commemorative gold coin series dated 1903. The coins were designed by Charles E. Barber, Chief Engraver of the United States Bureau of the Mint. The pieces were issued to promote the Louisiana Purchase Exposition held in 1904 in St. Louis. They were struck in two varieties at the urging of exposition authorities, including numismatic promoter Farran Zerbe: one depicted former president Thomas Jefferson, and the other, the recently assassinated president William McKinley. The price for each variety was $3, the same cost whether sold as a coin, or mounted in jewelry or on a spoon. Although not the first American commemorative coins, they were the first in gold. They were intended to help fund the Exposition, originally scheduled to open in 1903. Congress authorized the coins in 1902, but they did not sell well, and most were later melted. They regained their issue price by 1915, and are now worth between a few hundred and several thousand dollars, depending on condition.