Field Notes - These arches at Fort Pickens have withstood the test of time.  The fort was completed in 1834 on Santa Rosa Island to protect the city of Pensacola and entrance to Pensacola Bay.  Across Pensacola Pass stood Fort McRae (no longer standing).  It's interesting to note that Fort Pickens, although located in the deep South, remained under Union control for the duration of America's Civil War.  Fort Pickens was only one of three forts in the south to do that.  Fort Pickens also played a part in World War Two as part of the American coast watch system.  It's main purpose was to watch for German submarines.  It may shock some people to learn that German submarines were common in the Gulf of Mexico during WWII, but they were. Fort Pickens was decommissioned in 1947 and is now part of the Gulf Islands National Seashore.