From Freemasonry in Buenos Aires by Ian Thum:
Freemasonry in Buenos Aires was started with the consecration of a “Logia Independencia” in 1795 consisting of young intellectuals mostly with higher European degrees. Some of the most prominent members were Juan José Castelli, his cousin Manuel Belgrano, Juan José Paso, Feliciano Chiclana, Matías Irigoyen, Nicolás Rodríguez Peña, Hipólito Vieytes, Juan Larrea, Domingo Matheu and Antonio Luis Berutti.
Going forward in time and leading up to May 25, in 1808 Don José de San Martín joined his first lodge, the “Logia Integridad” in Cadiz, where the Worshipful Master of the lodge was General Francisco Solano, Captain General of Andalucia. It was at this time that San Martin, who was only a junior Mason at the time, met Lord Mac Duff, a noble Scotsman, who was plotting the liberation of South America.
San Martín travelled to England where he was put into contact with Alvear, Zapiola, Berro and Guido who formed part of the Lodge Lautaro created by Francisco de Miranda, who along with Bolívar, were already fighting in Venezuela for its liberation.
On March 9, 1812 San Martín arrived in Buenos Aires on board the Royal Navy Frigate George Canning direct from London, accompanied by a group of high ranking military personnel such as Chilavert, Zapiola, Carlos de Alvear, Arellano and Baron Olambert.
It is interesting to note that the First Triumvirate in 1811, the Second in 1812, the Declaration of Independence in Tucumán in 1816, the Constituent Assembly in 1853 and the Assembly of 1860 were mostly formed by Masons.
By this time there had already been a large immigration from the British Isles and Europe in general and it was on 10 June 1853 in Buenos Aires, that the first English Lodge working under English rule was consecrated. This was “Excelsior Lodge” under the Mastership of Samuel Hesse.
To this day, Excelsior Lodge No. 617 continues to meet regularly in Buenos Aires.
On 5 December 1861 and thanks to the intervention of Excelsior Lodge a Treaty was signed between the United Grand Lodge of England and the Grand Orient of the Argentine Republic whereby the United Grand Lodge of England recognises and acknowledges the Sovereignty and Independence of the Grand Orient of the Argentine Republic [sic] as a true Masonic Power located in Buenos Aires.
In 1861 Silver River Lodge No. 876 in Montevideo opened, in 1864 Star of the South Lodge No. 1025 and in 1872 Lodge of Harmony No. 1411 in Valparaíso followed, all three lodges are operative to this day.
Shortly after about 27 other English lodges were consecrated and started to operate in Buenos Aires, Rosario, Mendoza, Tucumán, Córdoba, Bahía Blanca, Campana, Quilmes, Villa Devoto, Hurlingham, Lomas de Zamora and Tigre.
English Masonry continues to this day working in Montevideo, Valparaíso, Buenos Aires, Córdoba city, Lomas de Zamora and Tigre, all under the District Grand Lodge of South America, Southern Division. This District covers Uruguay, Argentina and Chile.
The Grand Lodge of Argentina is headquartered in Buenos Aires at Perón 1242.
(Photo from Afterlife blog)