In the late 1930s as Nazi Germany began to seek European dominance, U.S. military planners became increasingly concerned about a German naval attack on the east coast of the United States. It became clear that new coastal fortiﬁcations and defenses were needed to potentially repel any invasion by the German Navy.
Thus, in 1938, the ﬁrst large artillery pieces were moved into what is now Cape Henlopen State Park (CHSP) then called Camp Henlopen. The ﬁrst large weapons moved to Camp Henlopen were four towed 155mm guns and were soon supplemented with 8-inch railway guns and deployed in two four gun batteries.
Later, in 1941, soldiers of the 261st Coast Artillery were called to active duty by the U.S. Army. Most of the men called up were from Sussex and Kent Counties (Delaware).
The 261st encamped in tents at Camp Henlopen, which then ofﬁcially became Fort Miles in August 1941. During the next four years, these artillerymen established themselves as one of the Army’s top performing coast artillery units.
As the German threat intensiﬁed, plans were drawn up to build two large underground artillery batteries to defend the mouth of the Delaware River. In March 1941, construction began on Battery Smith, which was to house two 16-inch guns. Battery Smith is located directly behind the Biden Center at CHSP. Construction of this casemated gun battery was completed in October 1942.
Following completion of Battery Smith, the Army Corps of Engineers immediately began construction of a second large battery in November 1942. Originally proposed as a second 16-inch battery, planners decided to transfer two 12-inch guns from Fort Saulsbury near Milford,
Delaware.The transfer took place in March 1943 and completion of the 2nd battery, named Battery 519, was completed in August 1943. The Fort Miles Museum is located in Battery 519, which is now open for public tours. During the same year, two smaller 6-inch gun batteries named Herring and Hunter were also completed.
Also, by 1943, permanent barracks and numerous other buildings such as a hospital and post ofﬁce were in place to house and provide services to the 2500 service men and women stationed at Fort Miles.
Fort Miles evolved into one of the largest fortiﬁcations built in the United States during World War II. Its large caliber guns controlled the Atlantic Ocean approaches to New Jersey, Maryland, Delaware and, most importantly, Delaware Bay. With casemates in both Delaware and New Jersey, the 16-inch, 12-inch and 6-inch guns of Fort Miles protected the tri-state area from enemy ships.
Integral to Fort Miles were ﬁfteen Fire Control Towers, which were used by forward artillery observers stationed at Fort Miles to locate shipping off the New Jersey, Delaware and Maryland coastline. Eleven of these “eyes of the Fort” were on the Delaware side of the Delaware Bay and four were on the New Jersey coast to spot the fall of projectiles shot from the large guns located in Battery Smith and Battery 519, along with the smaller 6-inch batteries.
As noted, the 11 Delaware towers occupy positions along the Delaware coast staring with Tower 1 in Fenwick Island, Tower 2 located 1.3 miles south of the Indian River Inlet Bridge, Towers 3 and 4 south of Dewey Beach and additional towers near Rehoboth Beach and Lewes.
Tower 7 in CHSP is open to visitors.
These towers were used to sight enemy surface ships and to assist sighting the mineﬁeld laid across the entrance to the Delaware Bay. The mineﬁeld was also deployed and operated from Fort Miles in the area now functioning as a ﬁshing pier.
In total, 16 underground structures were constructed with what is now Cape Henlopen State Park, including ﬁve artillery batteries. Additionally, the numerous support facilities included, as noted above, a hospital and post ofﬁce as well as a post exchange, ﬁre station
and an internal railroad system.
As World War II ended, Fort Miles was turned over to the U.S. Navy. The Navy established a top secret listening post to track Russian submarines, which operated at Fort Miles until 1963. Ultimately the entirety of Fort Miles was transferred to the State of Delaware.
Click here to gain more prospective through a video about Fort Miles.
Click here to watch an informative and inspiring documentary regarding Fort Miles entitled “Dunes of Defense.” This documentary was filmed by the United States Department of Defense.