He "was and remains the outstanding major Mexican investigator of his era, a fully accepted figure in the international group of his peers.
In 1892, at the commemoration of the 400th Anniversary of European contact with the New World, Del Paso y Troncoso was nominated president of the Mexican Commission on the American Historic Exhibition to be held in Madrid.
His extensive correspondence shows that he was always in contact with cultural institutions and specialists in his country and others from abroad that were also interested in the same field of research.
Many of these documentary collections were utilized by Charles Gibson, historian in his 1964 publication Aztecs Under Spanish Rule, which established in English-language scholarship the importance of the indigenous in the colonial history of Mexico.
Some of his other contributions include: Los libros de Anáhuac, México, 1895; Comentario al Códice Borbónico, Florencia, 1905.
Del Paso y Troncoso is a major figure in Mexican historiography, tirelessly tracking down manuscript materials in archives in Mexico and throughout Europe.
[4][5] By contrast, Mexican historian Silvio Zavala capably edited and published 16 volumes of Del Paso y Troncoso's Epistolario de Nueva España (1939–42).