The Fort of San Diego was built by the Spanish Empire to protect Acapulco from attacks by pirates, since the city was an important trading port, being the point of departure for the Manila galleons.

The fort was first built by Viceroy Diego Fernández de Córdoba, Marquis of Guadalcázar, and was completed in 1617 to designs of the Dutch military engineer Adrián Boot.

[1] The fort was extensively damaged in an earthquake in 1776, and it was demolished and rebuilt to designs of Ramón Panón.

The fort remained an active military installation of the Mexican Army, serving the Secretariat of War and Navy in the late 19th century.

[citation needed] It was handed to the Secretaría de Bienes Nacionales e Inspección Administrativa in 1949 in order to be converted into a military museum.