The Yellow Fever would have come from Asunción, Paraguay, brought by Argentine soldiers returning from the war just fought in that country, having previously spread in the city of Corrientes.

A witness to the epidemic of 1871, named Mardoqueo Navarro, wrote on April 13 the following description in his diary: Businesses closed, streets deserted, a shortage of doctors, corpses without assistance, everyone flees if they can...Since 1881, thanks to Cuban physician Carlos Finlay, it was known that the transmitting agent of Yellow Fever was mosquito Aedes aegypti.

[citation needed] Yellow Fever (or "black vomit", as it was called due to bleeding that occurs in the gastrointestinal) caused an epidemic in Buenos Aires in 1852.

[citation needed] Also, in the city of Corrientes, with a population of 11,000 and the centre of communication and provision for the allied troops between December 1870 and June of the following year, 2000 people died of yellow fever.

[citation needed] The filth and waste were used for levelling the terrain and streets in a city growing rapidly, mainly due to the influx of migrants.

[citation needed] The first census of Argentina in 1869 registered 177,787 inhabitants in the City of Buenos Aires, of which 88,126 were foreigners, and of those 44,233 were Italian and 14,609 were Spanish.

[citation needed] In addition to the epidemic of yellow fever that we have mentioned, there were outbreaks of cholera in 1867 and 1868, which killed hundreds of people.

The doctors Tamini, Salvador Larrosa and Montes de Oca warned the City Commission of the outbreak of an epidemic.

On 4 March, the Tribune newspaper commented that by night the streets were so dark "it truly appeared as if the terrible scourge had swept away all the residents".

So they created other emergency centres such as the Lazareto de San Roque (the Hospital Ramos Mejía today) and others were rented privately.

[citation needed] The port was quarantined and the provinces closed their borders to people or goods coming from Buenos Aires.

[citation needed] The municipality was unable to endure the situation, so on 13 March, thanks to a newspaper campaign started by one Evaristo Carriego (although not Evaristo Carriego, the journalist and poet, as he was not born until 12 years later), thousands of neighbours congregated in the Plaza de la Victoria (Plaza de Mayo today) to design a People's Commission of public health.

Other members included the national Vice President Adolfo Alsina, Adolfo Argerich, the poet Carlos Guido y Spano, Bartolomé Mitre, the canon Domingo César and the Irish-born priest Patricio Dillon who died in the epidemic and was named Carriego, who affirmed that "Even when so many are fleeing, that there are even some who stay in this place of danger to help those who cannot get regular assistance."

Among other things, the commission's function was to take charge of the streets and those who lived in places affected by the plague, and in some cases was sent to burn their belongings.

As the national and provincial authorities fled the city, the secular and regular clergy remained in their posts and conformed to their evangelical mandate, to help the sick and dying in their homes, and the Sisters of Charity stopped their teaching in order to work in the hospitals instead, although this was hushed up by the anticlerical writers of the time.

Then the knights Hector Varela, Carlos Guido Spano, and Manuel Bilbao among others took the decision to officiate at burials and rescued anyone from the mass graves who still showed signs of life, including a richly-dressed French lady.

The track started at the station Bermejo, located in the southwest corner of the street of the same name (Jean Jaurés today) where it joined the avenue.

The authorities who had not abandoned the city provided railway wagons as emergency living quarters in what is now Greater Buenos Aires and offered people free tickets to get out there.

On the aforementioned date of peak death, 10 April, the National and Provincial government decreed a holiday until the end of the month, which in reality was no more than official recognition of what was actually happening.

Then the count began to descend, perhaps helped by the first frosts of winter, falling to 89, but at the end of the month there was a new peak of 161, probably caused by the return of some people from the earlier evacuation.

[9] Many historians consider that this epidemic was one of the main causes of the reduction of the Black population in Buenos Aires,[10][11] because they mostly lived in the miserable conditions in the south of the city.

[citation needed] Many lawsuits began, related to wills suspected of being forged by criminals looking to make their fortune at the expense of the true heirs.

[citation needed] Juan Manuel Blanes, the Uruguayan painter who lived in Buenos Aires, painted an oil on canvas (currently in Montevideo) called The Episode of the Yellow Fever, reproduced in this article, inspired by one done during the tragedy, probably on 17 March 1871 in Balcarce Street.

[citation needed] Guillermo Enrique Hudson, the naturalist and writer born in Argentina, wrote a story in 1888 called "Ralph Herne", which goes through the epidemic of 1871.

In it he relates the following description: ...But the years of peace and prosperity did not delete the memory of that terrible period when during three long months the shadow of the Angel of Death extended over the city of the nice name, when the daily harvest of victims were thrown together—old and young, rich and poor, virtuous and villains—to mix their bones in a communal grave, when each day the echo of footsteps interrupted the silence less often, when like the past the streets became "desolate and grassy".