Scholars in Action presents case studies that demonstrate how scholars interpret different kinds of historical evidence. This cartoon, "Milk Tickets for Babies, in Place of Milk," created by Thomas Nast in 1876, comments on one debate that raged in the years following the Civil War: should the currency of the United States be based on gold (the "gold standard") or on paper (known as "greenbacks")? These debates about the nature of money, and the meaning of value itself, coincided with equally fundamental social and political debates about the nature of citizenship as it applied to the newly emancipated slaves. Political cartoons were a major form of commentary in late 19th-century American life, and Thomas Nast (1840–1902) was the most famous cartoonist of his day.