69.  After 100 years, the Louisiana Purchase was set in gold.  To remember the Louisiana Purchase on its 100th anniversary, the Mint made not one but two gold dollar coins—the first commemorative gold dollars. The dollars were sold at the 1904 World's Fair in St. Louis, held in honor of the Purchase. One of the coins had a picture of President Jefferson on the front, who was in office during the Purchase. The other showed President McKinley, who signed the law that financed the fair just before he was assassinated in 1901.