It’s bewildering at times, as a foreigner, to step outside on a perfectly salvageable Friday in Buenos Aires to find that nothing and nobody is working.

Happy Day of National Sovereignty! Today we slack off to mark the Battle of Vuelta de Obligado between the Argentine Confederation and a combined Anglo-French fleet attempting to force its way up the Paraná River on November 20, 1845.

This signal moment in Argentina’s history is immortalized in thrilling detail on the reverse of our 20 peso bill:

It’s almost too epic.

In terms of Argentine military defeats suffered at British hands that have been commemorated on currency, the Battle of Vuelta de Obligado ranks second only to the Islas Malvinas debacle and the sinking of the General Belgrano, which are depicted on the new 50 peso bills.

For it was a defeat. But it was a turning point as well.

Juan Manuel de Rosas and the Argentine Confederation

In those days, Argentina was not the federal republic we know today. From 1831 to 1852, the provinces were bound together in the Argentine Confederation, which lacked a true head of state — officially. In reality, the Governor of the Province of Buenos Aires, Juan Manuel de Rosas, called the shots on matters of foreign policy and trade and did his best to bend the other provinces to his will.

Rosas had a reputation then and now as a bit of a tyrant. He even had his own militarized para-police force: the dreaded Mazorca. But he had his moments, and the Battle of Vuelta de Obligado was one of them, so today you’ll find him enshrined on — you guessed it — the 20.
For a brief interval in the early 1830s when he relinquished his governorship (only to pick it up again in ’35), Rosas killed time by killing natives in the southern territories of Argentina. The woman in the heavy dress is his daughter, Manuelita
For a brief interval in the early 1830s when he relinquished his governorship (only to pick it up again in ’35), Rosas killed time by killing natives in the southern territories of Argentina. The woman in the heavy dress is his daughter, Manuelita. Because why not.
The Stand-Off
One tactic Rosas used to strengthen his position was to establish a monopoly on imports, insisting that all foreign trade be processed through the Buenos Aires customs office at the mouth of the Río de la Plata.
Like a greedy bridge troll, Rosas demanded tribute from anyone who passed by, even if their goods were destined for other Argentine provinces — or for another country entirely, like Uruguay or Paraguay. The British and French opted to ignore this edict outright, emboldened by the new technology of steam-powered ships, which could bypass Buenos Aires entirely and chug upstream against the current to trade directly with other cities along the Paraná River.
Rosas responded by blocking off the whole damn river at a narrow point called Vuelta de Obligado.
An enormous boom (nautical obstacle), consisting of 24 boats linked together by huge chains, was stretched across the river, trapping a number of foreign vessels upriver and shutting out 92 British and French merchant ships laden with goods headed for the interior territories. For the British, who saw themselves as indisputable rulers of waves (not without reason), this insolent challenge from the upstart Argentine Confederation was too good to pass up.
pew pew pew
pew pew pew
Challenge Accepted
A combined Anglo-French assault force of 11 warships was dispatched to breach the boom and force passage upriver for a swarm of eager merchant ships waiting in the wings. The boom was protected by Argentine artillery emplacements on a hill overlooking the river, plus a trio of gunboats.
The English and French had every possible advantage in firepower: their guns were bigger, more accurate, and they had a lot more of them. As an added bonus, the English deployed their patented Congreve rockets to calamitous effect against the Argentine shore batteries, which were too high for their cannon to fire on, and were thus believed to be unassailable.
The battle ended in a tactical victory for the imperialist aggressors, but the Argentines put up such a fight that the British and French later came willingly to the negotiating table. The British even pledged, in writing, to salute the flag of the Argentine Confederation with 21 guns.
This flag:
The flag of the Argentine Confederation (1850).
The flag of the Argentine Confederation (1850).
They could not afford another such “victory,” and the resulting treaties formally recognized the lesson learned at the Battle of Vuelta de Obligado: Argentina ain’t nothing to fuck with. Getting other countries to stop fucking with you is the essence of sovereignty, and our reason for the season.

*Ordinarily this feriado is observed on November 20, but the 2015 Argentine ballotage bumped it to the 27th. Nobody — not even an Argentine — wants to spend their holiday standing in line.

**If you feel I have overlooked or oversimplified any aspect of this story, please don’t hesitate to eviscerate me in the comments section. That’s what it’s for.