In the Spanish language, Argentina has always functioned as an adjective, not a noun. The earliest use appears to have been a 1602 poem, La Argentina ("The Silvery One") by Martín del Barco Centenera. In 1612, Tierra Argentina was used by Ruy Díaz de Guzmán. The use was inspired by the already established name Río de la Plata. In a fashion similar to Dominicana, the word Argentina has always been conceived as qualifying a noun, even when tacit, as in La Argentina.
The text of Art. 35 of the Constitution of 1853 as amended in 1860 appearing unchanged in all subsequently amended texts of the Constitution provides for the use of four styles:
Art. 35. Las denominaciones adoptadas sucesivamente desde 1810 hasta el presente, a saber: Provincias Unidas del Río de la Plata, República Argentina, Confederación Argentina, serán en adelante nombres oficiales indistintamente, para la designación del gobierno y territorio de las Provincias, empleándose las palabras Nación Argentina en la formación y sanción de las leyes.
Art. 35. The styles successively adopted from 1810 to the present, namely: Provincias Unidas del Río de la Plata, República Argentina, Confederación Argentina, shall continue to be official ones, interchangeably, for the style of the government and the territory of the Provinces, the words Nación Argentina being employed for the drafting and enactment of laws.
However, the authors of a report prepared at request of the National Academy of History by three of the most prominent Argentinian historians of the mid-20th century made clear the difficulties in providing a clear account of the polity styles formally used over the centuries.
The report approved by the Academy 26 Oct 1946 emphasises that since the date (25 Sep 1828) when Argentinian legislators for the first time used República Argentina as a term of reference to the nation and its parliament ("... proclamó el Sr. Presidente instalado el Cuerpo Nacional representativo de la República Argentina..." [Representación nacional, 20-21]) various styles were adopted, interchangeably, up to the Constitution of 1853.
Provincias del Río de la Plata
This style emerged as an ad hoc substitution for Virreinato del Río de la Plata (Viceroyalty of the Río de la Plata, and its versions) following the forced relinquishment by the viceroy Hidalgo de Cisneros de la Torre of his functions 23 May 1810. It was accepted by the Governing Junta of Buenos Aires as a term of reference to the loose federation of provinces which gradually recognised central authority and agreed to send their representatives to the Congress to decide on the future of the nation. While the summoning of the Congress continued to be delayed, the representatives of the provinces were incorporated into the Governing Junta in the end of 1810, providing a basis for forming a federal republic.
A group of the styles revolving around "Provincias Unidas" includes the most stable Provincias Unidas del Río de la Plata and less frequently used Provincias Unidas en/de Sud América and Provincias Unidas del Río de la Plata en Sud América.
Still lacking an opportunity to rely on the legislators representing the whole nation, the Governing Junta responded by assuming responsibility for federal legislation, occasionally replacing "Provincias" with "Provincias Unidas" in the texts of the laws. One of the earliest instances of using Provincias Unidas del Río de la Plata in official document is found in the decree of 1 Sep 1811, abolishing Indian tribute, issued by the Junta as "Junta Provisional Gubernativa de las provincias unidas del Río de la Plata, a nombre del Sr. D. Fernando VII" [Gaceta de Buenos Aires, Extra, 10 Sep 1811, pp. 659-661]. "Provincias Unidas" was also used as a polity style in Sec. 1 Art. 1 of the Provisional Constitution ("Reglamento"), providing for the division of powers:
"Los Diputados de las Provincias Unidas que existen en esta capital, componen una Junta con el título de Conservadora de la soberanía del Sr. D. Fernando VII, y de las leyes nacionales, en quanto no se oponen al Derecho Supremo de la libertad civil de los pueblos americanos." [Trabajos legislativos, 1:2-3; Registro nacional RA, item 257, 1:122-123]
The official style of the government was changed to "Gobierno Superior Provisional de las Provincias Unidas del Río de la Plata, a nombre del Sr. D. Fernando VII" in accordance with Art. 8 of the Reglamento ("Estatuto provisional"), approved by the government 22 Nov 1811 [Registro nacional RA, item 269, 1:127-128]. This style was proposed (31 Jan 1813) as a term of reference to the nation in promulgation of resolutions of the Constituent Assembly by executive authority [Trabajos legislativos, 1:12].
The Declaration of Independence of 9 Jul 1816 used Provincias Unidas en/de Sud América [Redactor del Congreso Nacional, No. 6, 23 Aug 1816, pp. 1-6; Gaceta de Buenos Aires, No. 68, 17 Aug 1816, pp. 277-278; Trabajos legislativos, 1:156-157; Registro nacional RA, item 936, 1:366-367]. Provincias Unidas en/de Sud América was also used in a Provisional Constitution of 3 Dec 1817 ("Reglamento provisorio") [Registro nacional RA, item 1144, 441-454], Constitución of 1819 [Registro nacional RA, item 1300, 495-508] and in the installation of the National Congress on 16 Dec 1824 [Diario Congreso, No. 1, 16 Dec 1824, p. 4; Trabajos legislativos, 2:31]; and never again, except for Provincias Unidas del Río de la Plata en Sud América shown in the minutes of the first session of the National Congress; and again - with the word "Unidas" missing - in a preliminary closed session, 29 Jun 1828 of the Convención Nacional.
Art. 3 of the statute on appointment of permanent national executive (6 Feb 1826) prescribed the style Presidente de las Provincias Unidas del Río de la Plata [Registro Nacional PRP, No. 2, 8 Feb 1826, pp. 30-31]. The decree of 7 Feb 1826 promulgating the resolution of the Congress on appointment of Bernardino Rivadavia as president referred to the office as Presidente de las Provincias Unidas del Río de la Plata, but another decree recognising him as office holder after his swearing-in used Presidente de la república de las Provincias Unidas del Río de la Plata [Registro Nacional PRP, No. 2, 8 Feb 1826, p. 33]. República de las Provincias Unidas del Río de la Plata was used in the preliminary peace treaty with Brazil (24 May 1827) [Registro nacional RA, item 2169, 2:192-193].
The only surviving style of this group is Provincias Unidas del Río de la Plata, which appears and disappears all the way to 1853; e.g., same session as first mention of Provincias Unidas del Río de la Plata en Sud América; session of 18 Jan 1825 (adoption of Ley Fundamental) [Diario Congreso, No. 9, pp. 214-261]; 3 Jul 1827 (act for organising the provisional government) [Registro nacional RA, item 2174, 2:196-197]; official mentions 1828, 1832, etc.
Provincias Unidas del Río de la Plata is embalmed as the only style in this group that remains, though dormant, as an official style (see Art. 35 above).
This has been the most tenacious style, sometimes the official or even Constitutional style, sometimes overriding the more technically official style - as it does currently both in daily use and on such official documents as postage stamps and coins; and as long used in the styles Presidente de la República Argentina (rarely in official use in the beginning of the presidency of Mitre, 1862-1868) and Presidente de la Nación Argentina (prescribed by Art. 74 of the Constitution as amended in 1860, but kept out of use until the presidency of Roque Sáenz Peña, 1910-1914).
The origins of the official use of República Argentina date back to the draft of the 1826 Constitution which was titled Proyecto de Constitución de la República Argentina. However, the only reference to República Argentina in the final version of the Constitution is found in Art. 68, confirming Presidente de la República Argentina as the formal style of the head of state. Three other articles of this document refer to Nación Argentina.
República Argentina continued in use by the Convención Nacional (first official session 25 Sep 1828); and it was used off and on from 1831 to 1853.
As noted, República Argentina continued in profuse official use; the Constitution of 1860 and all its amended versions to this day regard it, as noted in Art. 35, as an official style, in parallel with the "more" official style Nación Argentina.
Confederación Argentina was introduced by the Rosas régime as part of the heading officially approved for promulgating legislative acts by the decree issued 22 May 1835 [Registro Oficial Buenos Aires, No. 5, May 1835, item 871, pp. 124-125]. A typical decree passed under this regulation included a Gregorian date and three other dates counting the years of the Liberty, years of the Independence and years of the Confederation.
In 1836 the styles República de la Confederación Argentina and Provincias de la Confederación Argentina also appeared in official documents.
The style Confederación Argentina became invariable in all official documents from 1837, and is enshrined as the official style of the polity in the original text of the 1853 Constitution (passed 1 May 1853, promulgated 25 May 1853) [Congreso Constituyente (1852), 189-191; Registro nacional RA, item 3052, 3:65-73; Registro nacional RA, item 3054, 3:76]. Under its first amendment (1860) and all later amendments to this day Confederación Argentina remains embalmed as a technically official style.
The phrase "La Nación Argentina" first appeared in an official document in the preamble to the 1826 Constitution, but not as an official style; rather as "The Argentine body politic": "La Nación Argentina es para siempre..."
It occurred in this same manner in the Constitution of 1853: Art. 1: "La Nación Argentina adopta para su gobierno ...", whilst immediately declaring that the style is Confederación Argentina.
Nación Argentina became the declared official style of the polity with the 1860 amended Constitution, and all its successors to this day; although its Art. 35 mentions three other "official" styles - two antiquarian, one very much alive - it makes Nación Argentina the official style, (a) prescribing it for the texts of legislation, and (b) prescribing the style (Presidente de la Nación Argentina) for the head of state - a prescription promptly disobeyed in practice until recently, as noted.
Currently, "la Nación" occurs in many official contexts where in neighbouring polities the words would be "la República" (e.g., Banco de la Nación).