The Members of the Society of Jesus entered the Southern Cone region of Latin America in the late 1500s as missionaries to convert the Indian peoples. By the early 1600s there were over one hundred Jesuits in the region with settlements in such locations as Tucumán, Asunción, Buenos Aires, and Mendoza. They established the Universidad de Córdoba in 1622, one of the earliest universities on the continent. The Jesuits also explored the region opening up new areas to settlement.
Their missions in Paraguay and Argentina created domestic work and religious centers for Indians tribes, like the Guaraní. These plantations cultivated sugar, cotton, yerba mate, among other agricultural products.
Spain expelled the Jesuits from Latin America in the 1770s. The missions soon closed with Indians returning to their former way of life. After Pope Pius VII restored the order in 1814, they returned to Latin America, although Juan Manuel de Rosas, the Argentine dictator, expelled the Jesuits four years after allowing them to return in 1837. They returned to stay upon the invitation of José Justo Urquiza in 1852.
The archive currently consists of one undated letter, probably of about 1755. In the letter, the missionaries to the Guaraní complain about the terms of the Treaty of Permuta with Portugal and discuss the present condition of the Indians.