Answer:
27 february 1812.
Step-by-step explanation:
On February 27, 1812, General Manuel Belgrano, in the ravines of Rosario, on the banks of the Paraná River, flew the Argentine flag for the first time. He did it during the deed for the Independence of the United Provinces of the Río de la Plata.
Its blue and white colors come from the national cockade. History tells us that the original flag has been lost and some versions speak of having two stripes; others say they were three but it is not clear what their disposition was.
Belgrano first raised the flag next to the Libertad y Independencia batteries and was sworn in by the soldiers.
Communicating this fact to the Triumvirate, Belgrano left to take charge of the army of the North, without knowing that the public body denied him the possibility of using the new flag, due to the difficult situation prevailing.
Only after July 9, 1816, once the independence of the United Provinces of the Río de la Plata was declared, more precisely on July 20, its official use was approved by Congress.
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