Demand Notes are a type of United States paper money that were issued between August 1861 and April 1862 in denominations of 5, 10, and 20 U.S. dollars. Released during the American Civil War, these notes were used to pay expenses incurred by the Union during the war. They were popularly known as "greenbacks", a name inherited by their successors, the Legal Tender and Federal Reserve Notes.
Shown here is a $10 note, dated 10 August 1861, which includes an allegorical image of art on the right, and President Abraham Lincoln on the left; in the top center of the note is a vignette of a Bald Eagle perched on olive branches with a ribbon stating E PLURIBUS UNUM. This bill is scanned from the National Numismatic Collection at the National Museum of American History.
Banknote: Bureau of Engraving and Printing (image courtesy of the National Numismatic Collection, National Museum of American History)