In late December 1824 and early January 1825, approximately five years after Spain sold Florida to the United States for $5 million, U.S. Navy Commodore David Porter first inspected the Dry Tortugas islands. He was on the lookout to site to build a naval station that would help eliminate piracy in the Caribbean. Unimpressed with what he saw, he notified the Secretary of the Navy that the Dry Tortugas were unfit for any kind of the naval establishment. He reported that they consist of small sand islands a little above the surface of the ocean, have no fresh water, barely enough land to place a fortification, and in any case were probably not solid enough to bear one.
While Commodore Porter thought the Dry Tortugas were unfit for a naval station, there were others in the U.S. government thought the islands was indeed a good location for a lighthouse to guide ships around the area's reefs and small islands. An island called Bush Key, which was later called Garden Key, was was to be chosen as the site for the lighthouse, which became known as Garden Key Light. Actual construction began in 1825 and was completed in 1826. The 65-foot lighthouse was constructed of brick with a whitewashed exterior. A small white cottage for the lighthouse keeper was constructed beside the lighthouse.