[2] San Juan Antiguo is entirely located within the Isleta de San Juan, the islet off the coast of Puerto Rico where Old San Juan was settled, connected to the mainland by bridges and a causeway.

In the late 19th century, San Juan Antiguo called Plaza de San Juan is where Spain had its war fortifications and military buildings.

Puerto Rico was ceded by Spain in the aftermath of the Spanish–American War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States.

In 1899, the United States Department of War conducted a census of Puerto Rico.

This San Juan, Puerto Rico location article is a stub.