So-Called Dollars are a type of medallic coinage that emerged in the United States during the 19th century, particularly around the time of significant events or exhibitions. These pieces, often created to commemorate an event, organization, or notable figure, typically have a dollar size and may feature elaborate designs. The term "So-Called Dollars" was popularized by numismatist Harold E. Hibler in his 1973 catalog. One notable example is the So-Called Dollar SC 1, which was issued in 1869 to celebrate the completion of the Transcontinental Railroad, showcasing the historical significance of such pieces within American numismatics.