Postage stamps and postal history of Costa Rica change in currency from "Reales" to the new Pesos and "Centavos", the issue of 1863 was surcharged with new values for postal use: 1 Centavos, 2 Centavos, 5 Centavos (all over the Medio Real stamp), 10 Centavos (over Dos Reales) and 20 Centavos (over Cuatro Reales). The 5, 10 and 20 Centavos were also surcharged "U.P.U." Costa Rican stamps were issued overprinted "Guanacaste" in 1885-89 following war with Nicaragua over the sovereignty of Guanacaste. The first issue in the new "Colón" currency was dated 1900 and put into circulation in 1901. It consists of ten stamps with values ranging from
Gold standard Congress on March 3, 1903. Around the same time Mexico and Japan pegged their currencies to the dollar. When Siam adopted a gold exchange standard in 1908, only China and Hong Kong remained on the silver standard. When adopting the gold standard, many European nations changed the name of their currency, for instance from Daler (Sweden and Denmark) or Gulden (Austria-Hungary) to Crown, since the former names were traditionally associated with silver coins and the latter with gold coins. Governments with insufficient tax revenue suspended convertibility repeatedly in the 19th century. The real test, however, came in the form of