Hiking from Fort Totten to Fort Mahan

A Hiker’s Guide to the Civil War Defenses of Washington Fort Totten to Fort Mahan Self-Guided Tour First Edition March 2018 Library of Congress Civil War Defenses of Washington National Park Service US Department of the Interior 2 Dear Hiker, of Columbia (1902) This guide complements two similar hiking guides and a hiking and biking brochure (see “Resources”). Together, the opportunity to explore the Civil War Defenses of Washington on foot could become one of the most unique experiences in the region. The overall route—exceptional in the National Trails System--is recognized as a segment of the Potomac Heritage National Scenic Trail (PHT), a developing network between the mouth of the Potomac River and the Allegheny Highlands. We hope you enjoy the walk. Donald E. Briggs, Superintendent Potomac Heritage National Scenic Trail David N. Myers, Ph.D., ASLA, Associate Professor University of Maryland Designers: Beverly Hernandez and Sarah Whiteley (2018) Renee LaGue (2014) Jessica L. Heinz (2013) The PHT network in the region includes the C & O Canal Towpath; Mount Vernon Trail & PHT within George Washington Memorial Parkway; and Southern Maryland PHT bicycling route. Welcome The Civil War Defenses of Washington, built by Union troops between 1861 and 1864, are an engineering feat that transformed the vulnerable capital into one of the most fortified cities in the world. The 1902 “MacMillan Plan” proposed a vehicular parkway connecting the Civil War fortifications, many located on the topographic high points. Today the surviving sites–some with preserved or reconstructed earthworks–are green spaces woven into the past and present of neighborhoods in the midst of a densely populated city, and the connections between and among them reimagined as a “greenway” and a continuous route for pedestrian travel. “With the Anacostia and the Potomac below and the city of Washington spread out beyond and the hills of Virginia in the distance, these are the most beautiful of the broad views to be had in the District.” - MacMillan Commission Plan for the District 3 Trail Information Planning Your Visit For information on trail closures and alerts for Fort Totten and Fort Bunker Hill, visit Civil War Defenses of Washington at Rock Creek Park website (www.nps.gov/rocr) or call (202) 895-6070. For Fort Mahan information, visit the National Capital Parks-East website (www.nps.gov/nace) or call (202) 829-4650. Restaurants, gas stations, and convenience stores can be found around Fort Totten, along Eastern Avenue, and Benning Road. You can help protect the defenses! You play an important role in history when you visit the Civil War Defenses of Washington. For your safety and the preservation of the forts, do not climb on the earthworks– some are unstable and healthy vegetation helps to prevent erosion. All natural and cultural objects are protected by law. Stay on established trails and keep dogs on a leash. Leave rocks, animals, and wildflowers in place. Learn to identify and avoid poison ivy. Dial 911 for emergencies. Rock Rock Creek Creek NatureNature Center Center 4 Fort Totten Metro Station 1 Miles Metro and Capital Bikeshare Stations shown within 1/2 mile of Civil War Defenses of Washington Trail Fort Totten er st Ea Planning Your Visit n e nu e Av NE Fort Bunker Hill Brookland CUA Metro Station Ro N Ave rg il ns bu de Rho Colmar Manor Fort Community Park Lincoln Cemetery ad E nd Isla de ¯ 0.5 Bla 0 Route Overview: Fort Totten to Fort Mahan (11.4 miles) a ti os ac An Kenilworth Park & Aquatic Gardens National Arboretum ra rT ve Ri g la in ry sh a a M W n d to n d. ad Minnesota Ave Metro Station Fort Mahan C. Benning Ro 5 Washington, D.C. 1865 Map Courtesy of Library of Congress Background Information Fort Sites Highlighted in Blue 6 Engineering For War Library of Congress By 1864, Washington had become one of the most fortified cities in the world, with an encircling array of forts, batteries, and military roads. At the war’s end, Barnard reported that the defenses of Washington included 68 enclosed forts and batteries, emplacements for 1,120 guns (with 807 guns and 98 mortars actually mounted), 93 unarmed batteries with 401 emplacements for field-guns, twenty miles of rifle trenches, three blockhouses, and thirty-two miles of military roads linking the defenses. Library of Congress Library of Congress Background Information Minnesota Historical Society At the outset of the Civil War, the Federal capital of Washington, D.C. was not well-prepared to defend itself against potential Confederate siege or invasion. Reeling from the unexpected Confederate victory at First Manassas (Bull Run) in July 1861, the task of fortifying the capital fell to Major John G. Barnard (top right), the US Army’s chief engineer. Relying on the blueprints outlined by his West Point professor of engineering, Dennis Hart Mahan, in his Complete Treatise on Field Fortification (1836), Barnard marshaled Union troops, civilians, and escaped slaves to transform a largely rural area into a landscape of war. 7 Getting There Directions from Fort Totten Metro to Fort Totten Fort Slocum 0.6 mi McDonald Pl. NE NW sA ve nsa NE Ka R d. s Rd Rigg NW re Av e shi mp Ha NE w St Ne h Fort Totten en Dr NE ott tT 1,000 Feet For 500 North Capitol St. NW 0 Fort Totten is on your left up the gravel drive Fort Totten Metro Station Gallatin St. NW 0.2 mi 0.3 mi 4t Rock Creek Church Rd NE NE First Pl. NE Kennedy St. NW Mis sou ri A ve N W Blair Longfellow St. NW 0.1 mi Directions from Fort Totten back to Fort Totten Metro Station Turn right out of Fort Totten onto Fort Totten Drive NE Turn right on Gallatin Street NE and follow paved trail across field Turn right on First Place NE (no sign) and continue to metro station Fort Totten Metro Station is ahead of you 0.6 mi 0.3 mi 0.2 mi 0.1 mi Fort Totten Exit Fort Totten Metro Station and turn left onto 1st Place NE (no sign) Turn left on Gallatin Street NE and follow paved trail across field Turn left on Fort Totten Drive NE Madison St. NW 8 History Entrances to the forts were designated by main gates. Today, visitors and residents pass through a different kind of entrance near the original fort site: The Fort Totten Metro station. Library of Congress Library of Congress Library of Congress Fort Totten Fort Totten was constructed in 1862 on another topographic high point. It had an extensive field of fire guarding the approach to the US Soldiers Home (US Military Asylum), which then served as President Lincoln’s summer home. Fort Totten’s artillery consisted of 20 mounted guns and mortars, including eight 32-pounders. The 100 pounder Parrott rifle provided long-range support to Fort Stevens during the Confederate attack on July 11-12, 1864. 9 Exploring the Site Today Fort Totten Metro Station Gallatin St. NE Fort Totten Dr. NE North Capitol St. NE 1 300 600 Feet B s ate E .N Rd 3 Consider taking a 0.7-mile side trip to the Lincoln Cottage, operated by the National Trust for Historic Preservation. The Lincoln family lived at the US Soldiers’ Home during June-November of the years 1862, 1863, and 1864. This ‘military asylum’ was built on the third highest spot in the city in 1851, and served to care for disabled and retired veterans. The powerful guns atop the hill at Fort Totten helped to guard Lincoln’s frequent commutes from the White House to his family’s residence here. Fort Totten 2 150 Follow the gravel access road adjacent to the Fort Totten interpretive sign. In the wooded area at the top of the hill and to the right of the road, look for the parapet walls and dry moat. Beyond the walls and moat are earthen mounds that are the remains of the bombproof, an underground chamber protected by earth over a timber roof. 2 Compare the drawing here with the historic map on the previous page. Can you see the resemblance between today’s Fort Totten Drive and the military road shown on the earlier map? 3 0.7 mi 0 1 Getting There 10 0 0.25 Fort Totten Metro Station to Barnard Hill Park Ea n er st Open lawns and wooded forests of Fort Circle Parks are located on your left (north) ue en Av D N Continue onto Eastern Ave NE Fort Totten Turn left onto Varnum St NE Turn right onto Eastern Ave NE E ve aA ot ak h ut So Fort Totten E N You are hiking on the border of the District of Columbia and Maryland (Eastern Avenue NE) Barnard Hill Park !H !H Bunker Hill Park Brookland-CUA Metro E ¯ e od Rh 0.7 mi 322 ft 0.5 mi eN Av d an Isl Barnard Hill Park is on your right Turn right onto Randolph St NE The entrance path for Barnard Hill Park is on your right 0.1 mi Barnard Hill Park Fort Totten Metro !H 2.4 mi Exit Fort Totten Metro Station and turn right on Galloway St NE 0.1 mi Turn right onto South Dakota Ave NE 322 ft Turn left onto Gallatin St NE 0.7 mi a nd bi m yla ar olu M fC to ric st Di ¯ 0.5 Miles 11 History “From a few isolated works covering bridges or commanding a few especially important points, was developed a connected system of fortification by which every prominent point, at intervals of 800 to 1,000 yards, was occupied by an inclosed field-fort every important approach or depression of ground, unseen from the forts, swept by a battery for field-guns, and the whole connected by rifle-trenches which were in fact lines of infantry parapet, furnishing emplacement for two ranks of men and affording covered communication along the line, while roads were opened wherever necessary, so that troops and artillery could be moved rapidly from one point of the immense periphery to another, or under cover, from point to point along the line.” Library of Congress In 1864, he was appointed Chief Engineer, and was on the staff of General Grant in the Richmond campaign. He was made Major General at the end of the Civil War for “gallant and meritorious services in the field,” and was promoted to Chief Engineer of the Corps of Engineers December 28, 1865. Although he was promoted to full rank Colonel of Engineers, upon General Totten’s death, he asked that the nomination be withdrawn. He served out his career as Chief Regular Army Engineer until his retirement in 1881. Barnard Hill Park While Barnard Hill Park was not actually a location of a Civil War fortification, it bears the name of the individual who planned, designed and oversaw the construction of the forts protecting Washington, D.C., Brigadier General John G. Barnard. In Barnard’s A Report on the Defenses of Washington, published after the Civil War, he commented on the complexity and everchanging nature of the project: 12 0 Getting There 0.125 0.25 y ar of 1.2 mi a bi um l Co 0.2 mi 0.2 mi 0.8 mi n er st Ea ue en Av . ve aA ot ak E N ¯ . ve dA n sla eI od Rh NE You have arrived at Fort Bunker Hill. See following pages for information E Otis Street Fort Bunker Hill D " Randolph St. NE h ut So BrooklandCUA Metro N Barnard Hill Park Franciscan Monastery of the Holy Land Fort Bunker Hill to Brookland-CUA Metro 0.5 mi From the corner of 14th Street and Otis Street NE walk west on Otis Street NE Turn left onto Bunker Hill Rd NE Turn left onto Brookland Station Turn right to stay on Brookland Station Brookland Station is on your right 0.4 mi 259 ft 62 ft 203 ft You have arrived at Brookland CUA Metro Station. See following pages for directions from Fort Bunker Hill to Fort Lincoln Cemetery via Barnard Hill Park. Fort Bunker Hill nd la ct Turn right onto Randolph St. NE Turn left onto 24th St NE Turn left onto Otis Street Fort Bunker Hill is located on your right past 14th Street M ri st Di ¯ Barnard Hill Park to Fort Bunker Hill 0.5 Miles 13 History Defenses of Washington, 1865. National Archives Two 30-Pounder Parrots with ordinance: Library of Congress A May 17, 1864 report from the Union Inspector of Artillery noted the following: “Fort Bunker Hill, Capt. Charles Heine commanding.–Garrison, withdrawn; works guarded by Fourteenth Michigan Battery, from Camp Barry–1 ordnance-sergeant. Armament, eight 32-pounder barbette, one 8-inch siege howitzer, one Coehorn mortar, one 10-inch siege mortar, one 4-inch ordnance, two 30-pounder Parrotts. Magazines, one; dry and in good order. Ammunition, full supply and serviceable. Implements, complete and serviceable.” Fort Bunker Hill Fort Bunker Hill was built in the fall and winter of 1861-1862 by the 11th Massachusetts infantry. The fort was named after the Revolutionary fortification at Bunker Hill, Massachusetts. Fort Bunker Hill stretched over the hill with a perimeter of 205 yards. Within the fort, there were thirteen guns and mortars mounted that the soldiers used to defend the city. One of the Regiments that defended Fort Bunker Hill was the 11th Vermont Infantry Regiment. The 11th Vermont Infantry Regiment was the largest regiment sent from Vermont during the Civil War, totaling over 2,320 soldiers with recruits and transfers. Fort Bunker Hill was abandoned in 1865 at the end of the war. 14 Exploring the Site Today 4 1 3 2 2 An informational kiosk with phone and park information is located at the corner of Otis Street NE and 14th Street NE. Two picnic tables are also located at this corner in a small grassy opening. 3 From the corner of Otis Street NE and 14th Street NE, you can walk north on 14th Street NE. On your left is the wooded parcel where the earthworks were located. Here the woods and shrubs on the west facing slope are very dense. 4 You can then turn left (east) onto Perry Street NE and walk along the northern boundary of Fort Bunker Hill Park. Two blocks to the north is Michign Avenue NE which used to be named Fort Bunker Hill Road. 5 Turn left (south) again onto 13th Street NE to walk along the eastern boundary of Fort Bunker Hill Park. A beautiful American beech forest dominates the eastfacing slope of the park. At the end of the park will be Otis Street NE. Fort Bunker Hill 5 1 Little evidence of the Fort Bunker Hill earthworks is still visible today. 15 0.5 Miles l Co nd la bi um a ta ko e nu e Av NE Ea er n 0.8 mi 0.2 mi 0.3 mi e nu e Av e Av nd NW Fort Lincoln Cemetery ns bu rg Ro ad sla de o From the corner of 14th Street and Otis Street NE walk east on Otis Street NE Turn left onto 24th St NE Turn right onto Randolph St. NE Barnard Hill Park is on your left Barnard Hill Park is on your left as you approach Eastern Ave NE st e nu Rh 1.3 mi New York Avenue - I-50 Bridge to open in 2020 Barnard Hill Park to Fort Lincoln Cemetery 0.8 mi Turn right onto Eastern Avenue NE Head towards Bladensburg Road Turn left on Bladensburg Road Head north on Bladensburg Road (US-1 ALT N) 0.7 mi Fort Lincoln Cemetery is on your right 0.1 mi Fort Lincoln Cemetery y ar of Da Barnard Hill Park Bunker Hill Park I de Fort Bunker Hill back to Barnard Hill Park M t ric st Di th u So ¯ 0.25 Bla 0 Getting There 16 History Inscription on the Fort Lincoln Historic Marker. The Fort Lincoln Funeral Home and Cemetery grounds held the Lincoln Oak Tree. President Lincoln met with Civil War troops under a large oak tree where he discussed plans and strategies with the men. The tree was struck by lightning in 1994 and was destroyed, but the trunk remains with an informational plaque in front of it. In addition to the Civil War, the Battle of Bladensburg was fought near Fort Lincoln during the War of 1812. Just off site on the northeastern side of the Fort Lincoln Cemetery, is the historic Bladensburg Dueling Grounds that were active until 1868. The Bladensburg Dueling Grounds are located on the northern corner of the Fort Lincoln Funeral Home and Cemetery property. The grounds were used from 18081868 by military officers, politicians, and bureaucrats to settle their disagreements, both personal and political. The Bladensburg Dueling Grounds was one of the most active dueling grounds in the United States at the time, with approximately 50 duels taking place there. Each duel was governed by set etiquette that each participant followed. In 1839 a law was passed to end duels, yet duels continued to take place until 1868. Fort Lincoln Cemetery “These earthworks are a portion of the original fortifications which made up Fort Lincoln. This fort was built during the summer of 1861 to serve as an outer defense of the city of Washington. It was named in honor of President Lincoln by General Order No. 18, A.G.O., Sept. 30, 1861. The brigade of Major General Joseph Hooker was the first to occupy this area. In immediate command of the fort was Captain T.S. Paddock. The Civil War cannons have been placed here through the courtesy of the Department of Defense to commemorate this auspicious occasion.” View of the Bladensburg Dueling Grounds taken between 1910 and 1926. Library of Congress 17 History Library of Congress Library of Congress Fort Lincoln was armed with 34 guns and mortars that included: two 8-inch siege howitzers, six 32-pound seacoast guns, one 24-pounder siege, three 24-pounder seacoast guns, two 24-pounder field howitzers, four 12-pounder field guns, eight 6-pounder field guns, four 30-pounder Parrotts, one 100-pounder Parrott rifle, and one ten-inch and two 24-pounder Coehorn mortars. Fort Lincoln was defended by a number of units including the 1st and 11th Massachusetts Infantry, Hookers Brigade, 2nd New Hampshire Infantry, 26th Pennsylvania Infantry, and 1st Rhode Island Light Artillery, Co. D. Visible remains of Fort Lincoln include Battery Jameson trench that is northwest of the original fort, located in Fort Lincoln Cemetery and well preserved. Library of Congress Fort Lincoln Library of Congress Fort Lincoln was named after the 16th President of the United States, Abraham Lincoln. Fort Lincoln was more than double the size of Fort Bunker Hill, with a perimeter of 466 yards. The fort was constructed in the summer of 1861 by the 1st Massachusetts Volunteer Infantry. Within the fort was a 175-foot deep well that contained 100 feet of water to supply the troops. The fort complex also included rifle pits and exterior batteries to ensure the fort was well defended. 18 Exploring the Site Today 1 2 The remnant earthworks of Battery Jameson are found here. There is a 190 ft. section of the orginal 201 ft. battery wall. Two of the orginal four gun ports are also visible. Battery Jameson was manned by soldiers from nearby Fort Lincoln. 2 3 Fort Lincoln Cemetary is divided into a series of garden rooms. The upland area of the cemetary provides dramatic views to the east. 4 3 5 Military Rd. NW 4 Remants of Fort Lincoln earthworks can be seen in Fort Lincoln playgound which was built as part of Fort Lincoln New Town. 5 The Eastern Branch was renamed the Anacostia River. Fort Lincoln Cemetery 1 The entrance to Fort Lincoln Cemetery is located south on Bladensburg Road. 19 Fort Lincoln Cemetery to Fort Mahan (alt route) 0.5 Miles Fort Lincoln Manor Cemetary Colmar Community Park Turn left onto Bladensburg Rd Turn left onto Eastern Ave Continue onto Fort Lincoln Dr NE st Di ia Turn left on Bladensburg Rd (1.5 mi); Turn left onto 17th St NE (476 ft) ad Ro il bu rg New York Avenue - I-50 ns ia United States National Arboretum Anacostia River t os a Tr er T AR ( v Ri ac An Kenilworth Park & Aquatic Gardens United States National Arboretum Turn left onto M St NE Turn right onto Maryland Ave NE Turn left onto 22nd St NE (358 ft); Continue straight on I St NE (0.1 mi) Turn right on 26th St NE (0.1 mi); Turn left on Benning Rd NE (0.4 mi) Turn left and go under Benning Road to Anacostia River Trail (ART) Turn left onto Anacostia Ave NE Turn left onto Hayes St NE (0.3 mi); Continue onto Jay St NE (0.4 mi); Continue onto Nannie Helen Burroughs Ave NE Turn right onto Trail at Watts Branch Benning R Kin gm an Isla nd Turn right onto Hunt Place NE oad NE ART 0.1 mi 0.1 mi 0.4 mi 0.2 mi 0.2 mi 1.5 mi 0.5 mi 0.1 mi 0.1 mi 0.5 mi 0.7 mi 0.6 mi 0.7 mi Turn right onto Deane Ave NE Bridge to open in 2020 Alternative Route until 2020 Bridge Opening 5.7 mi Minnesota Avenue Metro Fort Mahan Turn left at trail along 42nd St NE 0.1 mi 456 ft 66 ft 0.2 mi Fort Mahan is straight ahead Fort Mahan to Minnesota Avenue Metro Turn left onto Grant St NE 0.2 mi Fort Mahan b nd um yla ol ar C M t of ric Turn right onto 31st Pl NE Turn right onto South Dakota Ave NE ) de ¯ 0.25 Bla 0 Getting There 20 On the Way to Fort Mahan Frederick Law Olmsted, Jr., was invloved in the 1902 MacMillan Plan that proposed a vehicular parkway connecting the Civil War fortifications. He was also involved in the initial plans to create a parkland along the Anacostia River. This hilly, 189-acre site, with the high point of Mount Hamiltoin, was established as a federally-funded research facility and arboretum by an act of Congress in 1927. The National Arboretum opened in 1959. A new bridge, expected to be built in 2020, will allow users to cross the Anacostia River and enjoy the many ffeatures of the National Arboretum. One of these Civila War era features is the Capitol Columns. “The columns began their life on the East Portico of the Capitol in 1828. They were quarried from sandstone near Aquia Creek in Virginia and were barged to Washington in the early days of our country, before the familiar Capitol dome was completed. Their stay at the Capitol was to be limited by an oversight. The dome of the Capitol, completed in 1864, appeared as if it was not adequately supported by the columns because the iron dome that was ultimately built was significantly larger than the dome that the designer envisioned. An addition to the east side of the Capitol was proposed to eliminate this unsettling illusion, but it was not constructed until 1958.” Red oaks (Quercus rubra) were collected from grounds of the Manassas National Battlefield Park, Virginia and the first and second battles of Bull Run. These trees are located in the National Arboretum. U.S. National Arboretum Bridge to open in 2020 21 From a Dec. 24, 1862 letter to Hon. E. M. Stanton, Secretary of War: “Fort Mahan may be considered an advanced tete-de-pont to Benning’s Bridge, and commands the valley of the Eastern Branch as far as Bladensburg, as well as the immediate approaches to the bridge. It is situated upon an isolated hill, the steep slopes of which are unseen from the fort, and are necessarily defended by external rifle-pits. As long as this work is held, an enemy cannot bring artillery to bear upon the bridge, nor move in force along the road which leads from Baldness-burg to the NavyYard Bridge.” Originally completed in 1861, Fort Mahan underwent numerous repairs and renovations. The intensive modifications resulted in a nine sided fortification totaling 354 yards. Fort Mahan included a guard house, barracks, officers’ quarters, a mess house, and stables and sheds. The parapet walls blocked views of the enemy approaches, causing them to build rifle pits on the surrounding steep hillsides. The fort had structures on every side of it to defend a full range of attack options. In the summer of 1865 when Civil War forts were being abandoned, Fort Mahan was one of the eleven forts retained. It was then given back to the original owner, the Manning Family. Authorized garrison: 531 infantry and 216 artillerymen. Fort Mahan was named for Dennis Hart Mahan, an American soldier and West Point Military Academy professor who taught civil and military engineering. Most Civil War commanders, both Union and Confederate, learned about fortifications and strategy from Mahan’s lectures and writing. Fort Mahan Fort Mahan was part of the fourth section of forts (terminating with Fort Greble) of the Defenses of Washington south of the Eastern Branch of the Potomac (Anacostia River). The main purpose of the Fort Mahan was to protect Benning’s Bridge. History United States Military Academy Library 22 Exploring the Site Today Av en ue M et ro 1 An entry path leads from 42nd Street NE up the hill to a large open meadow. M Av e nu e Fort Mahan 2 An open meadow is located in the hilltop area of Fort Mahan Park. The Washington Mounment is visible from selected vantage points. Some visible remains of earthworks, including a rifle battery, can be found on the hilltop. in ne s ot a Grant Street NE 1 4 4 A circular loop trail provides a wide variety of hiking experiences - from open clearings to densely forested. Fortification earthworks are clearly visible in north, south, and east locations of Fort Mahan Park. ning Roa dN E 3 42nd Street NE Ben 2 Georgia Ave NW M in ne so ta 3 A entry path to the circular loop trail is located along Benning Road on the south side of Fort Mahan Park. This area has open lawns and large canopy trees. 23 Potomac National Scenic Heritage Trail Regional Trail Network The route connecting the Civil War Defenses of Washington is part of a network of trails and routes between the mouth of the Potomac River and theAlleghenyHighlands.The Potomac Heritage National ScenicTrail network, a component of the National Trails System, is a means to explore contrasting landscapes on foot and by bicycle, horse, boat and cross-country skis. Sources and Additional Information: Civil War Defenses of Washington: www.nps.gov/cwdw Rock Creek Park (Fort Stephens, Fort Totten, Fort Bunker Hill): www.nps.gov/rocr National Capital Parks-East (Fort Mahan): www.nps.gov/nace District Dept. of Transportation: www.ddot.dc.gov Metro Rail and Metrobus: www.wmata.com Potomac Heritage National Scenic Trail: www.nps.gov/pohe Capital Trails Coalition: www.capitaltrailscoalition.org Cultural Tourism DC: www.culturaltourismdc.org Washington Parks & People: www.washingtonparks.net Cooling, B.F III. and W. H. Owen II. Mr. Lincoln’s Forts: A Guide to the Civil War Defenses of Washington. Lanham, Maryland: Scarecrow Press, Inc., 2010. National Capital Planning Commission. CapitalSpace: Ideas to Achieve the Full Potential of Washington’s Parks and Open Space. Washington, DC: NCPC, 2010. GIS Aerial Photo Basemap Source: Esri, DigtalGlobe, GeoEye, i-cubed, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community Resources Civil War Defenses / Additional of Washington Information National Park Service US Department of the Interior