He was the son of Eugenio María de Hostos and had several brothers and sisters: Eugenio Carlos, Luisa Amelia, Bayoán Lautaro, Filipo Luis Duarte, María Angelina[3] In 1939, he corresponded with his brother Eugenio Carlos de Hostos excitedly relaying how he hoped to have his publication, Trópico, be included in the newspaper Puerto Rico Ilustrado.
[4] De Hostos served in the United States Army from 1905-1919 rising to the rank of 1st lieutenant.
After his retirement in 1950, the position of Official Historian remained vacant for 43 years, until the Puerto Rico House of Representatives approved in 1993 Senate Concurrent Resolution 14, authored by Sen. Kenneth McClintock, designated Dr. Pilar Barbosa.
De Hostos spearheaded the excavation at a location in Guaynabo, finding remnants of early European settlement in Puerto Rico.
[6] Adolfo de Hostos died on October 29, 1982, in San Juan, Puerto Rico.