Colonel Gilberto José Marxuach a.k.a. "The Father of the San Juan Civil Defense", was a former officer in the United States Army who in 1951 founded and became the first director of the Civil Defense in the City of San Juan, Puerto Rico.

San Juan is the capital city and most populous municipality in the Commonwealth of Puerto Rico, an unincorporated territory of the United States. As of the 2020 census, it is the 57th-largest city under the jurisdiction of the United States, with a population of 342,259. San Juan was founded by Spanish colonists in 1521, who called it Ciudad de Puerto Rico.