The area around Benito Juarez, with its historical reference points being "La Tinta" and "San Antonio," was already within the lands that the national government planned to incorporate into the "civilized life of the country."

This lands constituted the vast extension where the famous native chief Cafulcura ruled, with his headquarters located in the area known as Salinas Grandes.

In the 1850s and following decades the biggest worry by the pioneers was the defence against the natives, who raze the region in order the steal the cattle, generating important human and economic loses.

Commander Nicanor Otamendi, from the Azul fort, under the orders of General Manuel Hornos, received the instructions to repeal the invasion by the natives.

In order to better manage the lands of the south, by Decree 544 of 31 August 1865 ten new partidos were created in Buenos Aires Province: Castelli, Tuyu, Ayacucho, Balcarse, Necochea, Tres Arroyos, Arenales, Rauch, 9 de Julio and Lincoln.

The land-owners, then, requested Mariano Roldan (the owner of a cattle establishment in the area of Tedin Uriburu) to petition to the authorities, since he had influential relatives and friends in Buenos Aires.

On 13 November 1866 Roldan wrote to his friend Dardo Rocha (who would later be governor of Buenos Aires) asking for information and requesting to speed up the procedures that had already been initiated.