Pedro Méndez Mercado was born in Ponce, Puerto Rico, on 26 June 1902.Auxiliar descriptivo de la Colección Pedro Méndez: Biographical or Historical Notes. Universidad de Puerto Rico at Rio Piedras. Archivo Arquitectonico y de Construccion. 2018. Accessed 14 March 2018. He was the second of eight children born to José Méndez López, a Spanish businessman with a store in Ponce across from Plaza de Mercado de Isabel Segunda, and Rosario Mercado Galarza, from Yauco, Puerto Rico. He studied in Ponce and graduated from Ponce High School in 1920.Auxiliar descriptivo de la Colección Pedro Méndez. Universidad de Puerto Rico, Recinto de Rio Piedras. Archivo Arquitectonico y de Construccion. 2018. Retrieved 14 March 2018.
