Van Middledyk's work was the first major historical study of Puerto Rico in English. Van Middledyk advanced Puerto Rican historiography by building on the works of Brau, Coll y Toste, and Acosta, and by consulting early Spanish chronicles. A librarian at the Free Public Library of San Juan, Van Middledyk possessed knowledge of and access to considerable primary source material. His history is sympathetic to the Indians and highly critical of Spanish colonial administration. Coming in the wake of American military occupation, the book sought to explain and justify control of the island by the United States.

The present English version, authorized by the publishers and heirs of M. Merimee, is based on the third French Edition. New material of two sorts has been added, however. First, the translator has been allowed to utlize an annotated, interleaved copy of the Precis, 1922, in which the author, and after his death his son Henri, himself a distinguished Hispanist, had set down material for the next revision. This accounts for many inserted names and phrases, and some paragraphs. Second, the translator has rewritten and added with some freedom.