The name "Argentina" comes from the Latin "argentum" (silver) and it is associated with the legend of the Saw of the Silver, common between the first European explorers of the region, both Spanish and Portuguese. It was the above mentioned who named Rio da Prata (River Plate) to the big estuary discovered by the Portuguese expedition of 1502 in which Américo Vespucio was taking part and to which then Juan Díaz de Solís came in 1516, calling it Mar Dulce.
The name made The Argentina popular because of a poem published in 1602 by the Spanish titled Martín del Barco Centenera to itself, in that the region of the River Plate is described as well as also the foundation of the city of Buenos Aires.  The place name turns out to be ratified after Ruy Díaz de Guzmán publishes in 1612 the work The manuscript Argentina of the Creole asunceno, acts of history in which, in the middle of an epic history, a description of the region is done. At the end of the XVIIIth century, the word was of common use to name everything related to the River Plate, his basin, his territory and his settlers, but the virreinato created in 1776, immediate precedent of the country made independent in 1816, it took the name of "Virreinato of the River Plate".
The First Governing body used the name of Close Provinces of the River Plate, which was used also by the governments that happened to him until, in 1816, the Congress of Tucumán proclaimed the independence of the Provinces Joined in South America, name that it supported in the Constitution of 1819.
Officially, Republic Argentina used for the first time the denomination in the Constitution of 1826. During the government of Juan Manuel of Roses (1835-1852) there used, between others, the names of Confederacy Argentina, the United States of the Republic Argentina, Republic of the Confederacy Argentina and Federation Argentina.