Early forts on the Delaware River Colonial period ca. 1650, showing their settlements and forts and the Dutch
Fort Nassau. Europeans came to the
Delaware Valley in the early 17th century, with the first settlements founded by the Dutch, who in 1623 built
Fort Nassau on the
Delaware River (which they called the South River, or
Zuyd Rivier in Dutch) opposite its
confluence with the
Schuylkill River in what is now
Brooklawn, New Jersey. Fort Nassau was a
factorij or fortified trading post. The Dutch considered the entire Delaware River valley to be part of their
New Netherland colony, which extended from what is now southern Delaware to Rhode Island. In 1638,
Swedish,
Finnish, and renegade Dutch settlers led by
Peter Minuit established the colony of
New Sweden at
Fort Christina (present-day
Wilmington, Delaware) and quickly spread out in the valley. In 1644, New Sweden supported the
Susquehannocks in their military defeat of the English colony of
Maryland. In 1648, the Dutch built
Fort Beversreede on the west bank of the Delaware, south of the Schuylkill near the present-day
Eastwick neighborhood, to reassert their dominion over the area. The Swedes responded by building
Fort Nya Korsholm, or New
Korsholm, after a town in
Finland with a Swedish majority. In 1655, a Dutch military campaign led by New Netherland Director-General
Peter Stuyvesant took control of the Swedish colony, ending its claim to independence. The Swedish and Finnish settlers continued to have their own militia, religion, and courts, and to enjoy substantial autonomy under the Dutch. The English conquered the New Netherland colony in 1664, though the situation did not change substantially until 1682 when the area was included in
William Penn's charter for
Pennsylvania, under which the city of
Philadelphia was founded. Penn's colony originally included both Pennsylvania and
Delaware; by 1704 the latter split off as the
colony of Lower Delaware, though the two shared a common governor. William Penn and many of the Pennsylvania colonists were
Quakers, members of a
pacifist Christian sect. They fostered good relations with
Lenape (Delaware) tribe, purchasing the colony's land from them, and had the only significant European settlements in the Americas without fortifications. In the 1740s French and Spanish
privateers entered the Delaware River, threatening the city. During
King George's War (1744–1748),
Benjamin Franklin raised a militia called the Association for General Defense, because the legislators of the city decided to take no action to defend Philadelphia "either by erecting fortifications or building Ships of War". He raised money to create earthwork defenses and buy artillery. The largest of these was the "Association Battery" or "Grand Battery" of 50 guns, on the site that became
Joshua Humphreys' shipyard in 1794 and is now the Coast Guard Station Philadelphia. At the end of the war, commanders disbanded the militia and left derelict the defenses of the city. With the outbreak of the
French and Indian War (part of the Seven Years' War) in the 1750s, plans were drawn up for a fort on Mud Island (later called
Fort Mifflin) in the Delaware at the southern end of today's city limits, but no fort was built. Eventually, in 1771 British General
Thomas Gage assigned Captain
John Montresor of the British
Corps of Engineers to the task of designing and building a fort on the island. Montresor submitted six designs to Penn and the Board of Commissioners, estimating £40,000 for an adequate fort with 40 guns and a 400-man garrison. His designs were all considered too expensive by the Board, which provided only £15,000 for purchasing the island and building the fort. Construction began in 1771, but in mid-1772 Montresor left the project and returned to New York. Work on the fort ended a year later, with only the east and south walls built.
Revolutionary War In April 1775 the
American Revolution broke out full-scale at
Lexington and Concord in Massachusetts. These battles were followed shortly by the convening of the
Second Continental Congress in Philadelphia on May 11, 1775. The Philadelphia
Committee of Safety, headed by
Benjamin Franklin, decided to protect the city by obstructing British access to the Delaware River. Three forts were built to protect two lines of
chevaux de frise obstacles in the river, designed by
Robert Smith. One line was at
Fort Billingsport, New Jersey, and another was between
Fort Mifflin (called "Fort on Mud Island" or the "Fort Island Battery" at the time) and
Fort Mercer. A third line of obstacles was downstream at
Marcus Hook with no forts nearby. Forts Mercer and Billingsport in New Jersey were designed by
Tadeusz Kościuszko and built as
earthworks; work also resumed on Fort Mifflin and all three forts were garrisoned during 1777. Meanwhile, the Continental Congress relocated to Baltimore in early 1776 due to a threat of British attack, later returning to Philadelphia and issuing the
Declaration of Independence on July 4, 1776, attracting further British attention to the city. In early 1777 the British planned to cut New England off from the rest of the colonies by sending a force under
John Burgoyne southward from Montreal through the Lake Champlain area and the Hudson Valley to Albany. This was intended to be supported by a force under General
William Howe advancing northward from New York City. However,
George Germain, a British civilian official managing the war in London, also gave approval for Howe to capture Philadelphia. Howe proceeded with the Philadelphia plan and largely failed to support Burgoyne's campaign. The Philadelphia campaign was time-consuming but successful; the British took a lengthy water route through Chesapeake Bay, then marched overland to defeat Washington at the
Battle of Brandywine southwest of Philadelphia on September 11, and entered the city unopposed on September 26. The
Continental Congress left the city ahead of the British occupation, moving first to Lancaster and then to
York, Pennsylvania. Howe had the luxury of bypassing most of Philadelphia's defenses, occupying the city following his victory at Brandywine. However, his primary supply route was the Delaware River, with the forts and lines of
chevaux de frise blocking it. They cut through the line near Marcus Hook without opposition, and easily took
Fort Billingsport and its line of obstacles on October 2. They then laid siege to
Fort Mifflin and
Fort Mercer, unsuccessfully attacking the latter by land and river in the
Battle of Red Bank on October 22. The 1,200
Hessians of the assault force suffered over 350 casualties, the British also losing (64 guns) and HMS
Merlin (18 guns) to grounding. The latter was possibly an indirect result of engagement by the
Continental and
Pennsylvania navies, which also provided
enfilading fire against the Hessians. The siege was commanded by
John Montresor, designer of Fort Mifflin. On November 10 bombardment of the fort began in earnest. The fort was evacuated and burned (to impede its use by the British) five days later, with the
Patriot forces of over 400 men suffering about 250 casualties. Fort Mifflin was "entirely beat down; every piece of cannon entirely dismounted", as reported by George Washington. On November 18, Fort Mercer was evacuated in the face of a British force of 2,000, their artillery having breached the fort's walls. Burgoyne's campaign came to a defeat in the
Battles of Saratoga, leading to his eventual surrender on October 17. This victory persuaded France to enter the war on the Patriot side. Word of it reached Commissioner
Benjamin Franklin in Paris on December 4, and negotiations resulted in
France declaring war on Britain in March 1778. Washington and his army encamped at
Valley Forge in December 1777, about 20 miles (32 km) from Philadelphia, where they stayed for the next six months. Over the winter, 2,500 men (out of 10,000) died from disease and exposure. However, the army eventually emerged from Valley Forge in good order. Meanwhile, there was a shakeup in the British command. General Howe resigned his position, and was replaced by Lieutenant General
Henry Clinton as commander-in-chief. France's entry into the war forced a change in British war strategy, and Clinton was ordered by the government to abandon Philadelphia and defend New York City, now vulnerable to French naval power. Clinton shipped many Loyalists and most of his heavy equipment by sea to New York, and evacuated Philadelphia on June 18, 1778. Washington's army shadowed Clinton's, and Washington successfully forced a
battle at Monmouth Courthouse on June 28, the last major battle in the North. Washington's second-in-command, General
Charles Lee, who led the advance force of the army, ordered a controversial retreat early in the battle, allowing Clinton's army to regroup. By July, Clinton was in New York City, and Washington was again at
White Plains, New York. Both armies were back where they had been two years earlier. The military focus of the war shifted to the southern colonies. Eventually, the American victory in the
Yorktown campaign on October 19, 1781 proved to be the key to independence; the British received word of it on November 25. This precipitated a collapse of
Lord North's
Tory government in March 1782. The new
Whig government suspended offensive operations in the Thirteen Colonies and commenced lengthy peace negotiations, culminating in the
Treaty of Paris that ended the war on September 3, 1783.
1783–War of 1812 The ruins of Fort Mifflin lay derelict until 1793, when rebuilding began under what was later called the
first system of US coastal fortifications.
Pierre L'Enfant, also responsible for planning
Washington, D.C., supervised the reconstruction and designed the rebuild in 1794. Reconstruction work began on the fort in 1795 under the auspices of engineer officer
Louis de Tousard, who from 1795 to 1800 worked on coastal defenses between Massachusetts and the Carolinas. The initial goal was to rebuild the fort to accommodate 48 guns. The army officially named the fort after
Thomas Mifflin, a
Continental Army officer and the first post-independence
Governor of Pennsylvania, in 1795. Rebuilding the fort consumed $94,000 of a total fort budget of $278,000 in 1798 and 1799 alone (in 1799 money). Also, the U.S. Congress met in Philadelphia until 1800 and Fort Mifflin was well garrisoned until then, usually with two companies. During the
War of 1812 efforts were made to fortify
Pea Patch Island, later the site of
Fort Delaware. This was the first of three times new defenses were built further seaward along the Delaware as gun ranges increased; the river
estuary widens rapidly downstream of the island and at the time rendered smoothbore
cannon defenses ineffective. This plan of defense was largely coordinated by Capt. Samuel Babcock, who was working nearby on similar defenses in Philadelphia. During this time a
seawall and
dykes were built around the island. There is no known evidence that any progress was made on the actual fortification by war's end. The original plan was to build a
Martello tower on the island. Other sources state that an
earthwork fort was built on the island during the war and demolished in 1821; also, a wooden fort existed from 1814 to 1824.
Battery Park in
Delaware City is on the site of the Delaware City Battery, an earthwork erected in 1814.
1815–1860 .'' In 1815 the first
Fort Delaware was designed by
Joseph G. Totten and construction soon began on
Pea Patch Island. This fort was in the shape of a
five-pointed star, with large
bastions and short
curtain walls. The five-pointed star design is viewed as "transitional" between the
second and third systems of US fortifications. Capt. Samuel Babcock supervised the work from about August 1819 until August 20, 1824. Completion of the project was delayed years past the proposed date due to uneven settling, improper pile placement and the island's marshy nature. In one occurrence an entire section of 43,000 bricks had to be taken down, cleaned, and reworked due to massive cracking. In 1822, Colonel Totten and General
Simon Bernard were on the island to inspect the faulty works. Captain Babcock was severely criticized for altering Totten's plans without orders. Babcock subsequently appeared before a
court-martial for his actions in late 1824. It was determined he was not guilty of neglect but rather error in judgement and he was acquitted. The fort on the Delaware shore may refer to the Delaware City Battery; a permanent battery was not built there until the Civil War. The star fort was garrisoned prior to 1825. In 1831 it was wrecked by a fire. Captain
Richard Delafield was tasked with designing and building a replacement; the first fort was demolished in 1833. The new fort was intended, in Capt. Delafield's words, "as a huge bastioned
polygonal form to be built in masonry." It appears no further work was done on this fort. The present Fort Delaware was erected mainly between 1848 and 1860 as one of the larger forts of the
third system of US fortifications. Although major construction was wrapped up before the
Civil War broke out in 1861, the post engineer did not declare the fort finished until 1868. The fort was designed by Army chief engineer Joseph G. Totten, and construction was supervised by Major John Sanders. The fort was about the size and location of the previous star fort. It was in the shape of an irregular pentagon, with five small bastions at the corners, called "tower bastions" by Totten. Four of the sides were seacoast fronts, with three tiers of
cannon on each, two
casemated tiers in the fort and one
barbette tier on the roof. The irregular shape provided for more cannon on the east-facing fronts, where the deeper channel was. A total of 123 heavy cannon could be mounted on the seacoast fronts, with 15 more in the bastions. The long rear front was called a "gorge wall", with two tiers totaling 68
loopholes for muskets and a tier of 11 cannon on the roof. In the center of this wall was the
sally port, the only entrance to or exit from the fort. Twenty short-range flank
howitzers could be mounted in the bastions to defeat attacks on the
curtain walls. Thus, the fort had positions for 169 cannon. The fort also had a
moat, with a
tide gate on a canal from the river to control the moat's level.
1861–1885 Fort Delaware was used as a
prisoner-of-war camp for
Confederates for most of the Civil War. Convicted
Union Army soldiers and local
political prisoners were also held there. By August 1863 over 11,000 prisoners were on the island, and during the war a total of 33,000 were housed there at some time. About 2,500 prisoners died on Pea Patch Island during the war. Half the total deaths were in a
smallpox epidemic in 1863. Many of the Confederate prisoners and Union guards who died at the fort are buried in the nearby
Finn's Point National Cemetery in
Pennsville, New Jersey. The Ten Gun Battery, briefly called Camp Reynolds or Fort Reynolds, was built from 1863 to 1864 on the property of 1st Lt. Clement Reeves of the
5th Delaware Volunteer Infantry, on the Delaware shore near Fort Delaware, now on the
Fort DuPont property. Sgt. Bishop Crumrine of Young's Battery wrote, "This fortification is not properly a Fort but rather a water battery. Situated just across the river from Fort Delaware on the Delaware City side, it has five sides. The two longest sides being next to the river is a heavy breast work on which six 10-inch and four 15-inch
Rodman guns are mounted." The Civil War had shown that masonry forts were vulnerable to modern rifled cannon, particularly in the
siege of Fort Pulaski near Savannah, Georgia in 1862. New earthwork forts were built in the 1870s, including reconstruction of the Ten Gun Battery as the Twenty Gun Battery and the new Battery at Finn's Point, later the site of
Fort Mott. Both were to house heavy guns and coast defense mortars, but were not completed or fully armed, as construction funding for forts was cut off in 1878. In 1876 a mine casemate was built near the Twenty Gun Battery to control an
underwater minefield, one of the first defenses of this type in the US. A similar casemate was built around the same time at
Fort Mifflin, but was not used.
Endicott period The
Board of Fortifications was convened in 1885 under
Secretary of War William Crowninshield Endicott to develop recommendations for a full replacement of existing coast defenses. Most of its recommendations were adopted, and construction began in 1896 on new batteries and
controlled minefields to defend the Delaware. Fort Delaware was modernized with a large new gun battery inside the stone fort and small-caliber batteries on and outside the fort. The other forts were on the shores flanking Pea Patch Island. Fort Mott was built as both a seacoast fort and to defend against a land attack, reusing some of the 1870s Finn's Point Battery. Fort DuPont received all-new gun batteries, including a battery for 16 mortars. The three forts became known as the Coast Defenses of the Delaware. This appears to have initially been an Artillery District, was renamed as a
Coast Defense Command in 1913, and again renamed as a
Harbor Defense Command in 1925.
Fort DuPont had a battery of sixteen
mortars in an "Abbot Quad" arrangement for concentrated fire. Two guns on
barbette carriages and two
guns on disappearing carriages were in an unusual arrangement: the 12-inch guns were on either side of the pair of 8-inch guns. Two two-gun batteries, one with
guns and one with 3-inch guns, completed the armament. Unusually, weapons were removed from CD Delaware prior to the US entry into World War I to arm higher-priority defenses. In 1910–1913 a 5-inch gun battery at Fort Mott was relocated to
Fort Ruger, Hawaii. Some weapons were removed from forts with the intent of getting US-made artillery into the fight. 5-inch and 6-inch guns became
field guns on wheeled carriages. 12-inch mortars were also removed as railway artillery or to improve reload times by reducing the number of mortars in a pit from four to two; this happened at Fort DuPont to provide mortars elsewhere. The remounted 5-inch and 6-inch guns were sent to France, but their units did not complete training in time to see action. In 1917–1918 a number of weapons were relocated away from CD Delaware; only two were returned. Four mortars from Fort DuPont were used to arm
Fort Rosecrans in San Diego, California. The remaining 5-inch guns at Fort Mott were removed for use as
field guns. In 1919-1920 several weapon types were declared obsolete and removed from coast defenses. These included all 5-inch guns, all Armstrong guns (6-inch and 4.72-inch), and 3-inch M1898 guns. Only in rare cases were these weapons replaced. In CD Delaware this meant the removed 5-inch guns were not returned, the 4.72-inch guns were removed as war memorials, and three 3-inch batteries were scrapped. These were the two batteries on top of Fort Delaware and Fort Mott's unique casemated 3-inch battery.
World War II Early in World War II numerous temporary buildings were again constructed at the forts to accommodate the rapid mobilization of men and equipment. In 1940–41 the
21st Coast Artillery Regiment was mobilized at Fort DuPont with a strength of one battalion to garrison the Harbor Defenses of the Delaware (HD Delaware). On January 27, 1941 the
261st Coast Artillery Battalion was activated and moved to Fort DuPont, with elements moving to Fort Miles on June 5, 1941. On April 15, 1941 the 21st CA deployed
155 mm gun batteries at
Fort Miles and activated
Fort Saulsbury. The first batteries at Fort Miles and Cape May were four mobile 155 mm GPF guns each, deployed in April 1941 at Fort Miles and some time later in 1941 at the
Cape May Military Reservation in New Jersey. After the
attack on Pearl Harbor on December 7, 1941 building up Fort Miles became a higher priority. By mid-1942 concrete "
Panama mounts" were completed for the 155 mm gun batteries. The
US Navy also participated in defending the Delaware with
net defenses and a
defensive boom at
Reedy Island. Submarine-detecting
indicator loops were also used, with a station at Fort Miles. As Fort Miles' batteries were completed, the remaining weapons at the forts on and near Pea Patch Island were removed or scrapped. Fort DuPont's mortars were effectively out of service in 1941; in December 1942 the carriages were ordered scrapped, followed by the mortars in April 1943.
Cold War Following the war, it was soon determined that gun defenses were obsolete, and they were scrapped by the end of 1948, with remaining harbor defense functions turned over to the Navy. followed by
Nike missile systems in the late 1950s (see List of Nike missile sites#Pennsylvania and List of Nike missile sites#New Jersey). The Nike missiles were removed in the early 1970s. Battery 221 a.k.a. Battery Herring, originally covered with sand like all the other batteries, was excavated and expanded for use as a
U.S. Navy SOSUS station during the Cold War as part of Naval Facility (NAVFAC) Lewes. It is now abandoned. ==Present==