La Republica de Argentina is the successor State of Spain in the Southeastern portion of the former Spanish empire in the Americas. At the time of independence, first declared in the Viceroyalty of Buenos Aires in 1810, the territory included present-day Argentina, Uruguay, Paraguay, and Bolivia. The region became known as the United Provinces of the Rio de la Plata. The territory was administered by the government in Buenos Aires. The Congress of Tucuman issued a formal Declaration of Independence in 1816. Shortly thereafter, Uruguay, Paraguay, and Bolivia established independent nations and the remaining territory formed Argentina.
Miguel-Stearns, Teresa M., "Argentina, SOURCES OF STATE PRACTICE IN INTERNATIONAL LAW." (2014). Librarian Scholarship Series. 36.