Argentina was known as the "United Provinces of the Rio de la Plata" from 1810 to 1825, after a revolt and separation from Spain. They took the name "Argentina" in 1825 and are usually referred to by that name. In 1818, Argentina commissioned a privateer named Hipólyte Bouchard to raid Spanish shipping. On November 20, 1818, his two ships, the La Argentina and Santa Rosa, attacked the California coastal town of Monterey. The raiders held the town for six days and then left and headed south. The ships then attacked another California town, San Juan Capistrano. They then headed to Mexico for more raiding and then back to South America. The raid on the two California towns is known as California's only attack by pirates.

Silver, 38 mm, 26.80 gm
Obverse:
Sun face and rays
PROVINCIAS DEL LA RIO DELA PLATA (Provinces of the Rio de la Plata)
Reverse:
Wreath, two hands holding Liberty Cap
EN UNION Y LIBERTAD
1813
Mintmark: Monogram for Potosí, Assayer initial 'J'