With the commercial activity increasing considerably, it was decided to create a post service at Buenos Aires.

[6] Post service in Argentina played a key role during the May Revolution because of orders and reports from the Primera Junta were distributed through letters.

In 1826, during the presidency of Bernardino Rivadavia, the service was nationalised by a Law passed by the Congress of Provincias Unidas del Río de la Plata.

During successive administrations, money orders, courier services, registered letters and declared values were implemented.

Works started in 1889, not being finished until 1928 when the building was officially inaugurated by president of Argentina Marcelo T. de Alvear.

The contract of concession set a term of 30 years, also establishing that SOCMA would pay a six-monthly rent of A$ 51.6 million to the state.

[12] Only a small part of the building continued its activities as a post office and sale of stamps, on Sarmiento street.

[14][15] In 2004, the re-privatization plan was halted, and a new state-owned S.A. corporation was created: Correo Oficial de la República Argentina Sociedad Anónima.