Silver certificates are a type of representative money issued between 1878 and 1964 in the United States as part of its circulation of paper currency. They were produced in response to silver agitation by citizens who were angered by the Coinage Act of 1873, which had effectively placed the United States on a gold standard. Since 1968 they have been redeemable only in Federal Reserve Notes and are thus obsolete, but they remain legal tender at their face value and hence are still an accepted form of currency. These are six banknotes from the 1880 series of large-size silver certificates, designed by the Bureau of Engraving and Printing and comprising eight denominations from $1 to $1000. Each banknote bears a portrait of a different individual, identified above.Banknote design credit: Bureau of Engraving and Printing; photographed by Andrew Shiva