When the Civil War began, Americans starting hoarding coins, as the metals they were made of were bound to become scarce. This caused a shortage of coins, and the U.S. mint responded by issuing paper currency in fractional denominations, like three cents, five cents, up to fifty cents. The state of our currency system was changing so rapidly that mistakes were bound to happen, and Superintendent of the National Currency Bureau Spencer M. Clark knew it.
It was the third issue of that five-cent note that caught Clark’s attention. Congress had asked for the note to honor William Clark of the Lewis and Clark explorations. But allegedly, the document that reached the Treasury specified only that the new bill should honor “Clark,” without clarifying which one—and Spencer M. Clark, despite surely knowing Congress’s true intention, seized the opportunity to print his own face on the bill.
William Clark, Spencer Clark, what difference does it make? Spencer was in hot water with Congress already, and they didn't take to his latest shenanigans one bit. Read what happened when Clark put his own face on the five-cent bill at Atlas Obscura.