Before the arrival of Europeans, this area was populated by different native tribes including Querandies, Baguales, Chanas, and Caaguanes both in the mainland and on the numerous islands of the District of San Pedro. They gradually disappeared under the influence of the Spanish.
After the second founding of Buenos Aires during the colonization process Don Juan de Garay divides the territory amongst his troops and aides with the goal of maintaining power over the land.
In 1641, control was given to Don Pedro Gutierrez Humanes but only eight years later his son, Juan Humanes made these lands productive and obtains even more land in 1651 totaling 1,319 square kms, which is today the San Pedro District.
The pueblo of San Pedro started growing at a place called “Rincon de San Pedro de Arrecifes”. King Fernando VI authorized the construction of the Franciscan Fathers 26 August 1748.
The convent was made bigger in 1774 to make it possible to build a school where to teach Latin and Discoursing. The well-known Fray Cayetano Jose Rodriquez member of the liberation of the country and prominent in the politics of the country studied in these classrooms. The District of San Pedro was created 30 December 1784.
Some other internal affairs battles took place in this region like the one of 1882 on the cliffs and the one in Plaza Constitucion after Dorrego’ overthrow, confronting forces loyal to the Governor who had been shot and those loyal to General Lavalle commanded by Captain Juan Damaso Camelino.
There was another battle in 1840 after general Juan Lavalle landed in San Pedro. The Vuelta de Obligado Battle took place here 20 November 1840. After 1854 as a result of the law of municipal organization, a new system of Deliberation Councils was formed, integrated by municipal members elected by the people. San Pedro was declared a city 25 July 1907 by Law 3040.