The story
Hermanos Porrúa has over 100 years of history as bookseller and publisher in Mexico. In the second half of the 19th century, three brothers emigrated from Spain to Mexico City: José, Indalecio and Francisco Porrúa. Indalecio had a market stall on what is now Del Carmen Street, north northwest of the Zócalo, in which he had a sign stating that he bought and sold libraries. His business was successful enough that he asked his brothers to join him. The libraries that they purchased were important not only for the works that they contained but also because from whom they were purchased, including some of the Mexico City's nobility. They published Mexico's first bibliography called the "Boletín Bibliográfico" which categorized the antique books for sale. It and others like it would set the value of most of the antique books in Mexico over the following century.
From Wikipedia’s article on Librería Porrúa, shared under CC BY-SA 4.0.3