When Woodrow Wilson declared war upon Germany in April 1917, the United States entered the war in Europe on the side of the Allied Powers. Compared to the air services of its Allied Powers, the Aviation Section of the US Signal Corps (the US military aviation) was still in its infancy. In May 1918 it was transformed into the Army Air Service of the American Expeditionary Force (AEF). In total, 45 AEF squadrons saw action on the Western Front, 18 of which were observation units (Anon. 1962). The Americans also applied aerial photography at the Western Front (Maurer 1978), but only after a learning period based on British and French examples, simply because virtually no experience in aerial photography was gained by the Americans before the declaration of war (Finnegan 2006).
The search for unexploited archives containing World War One aerial photographs directed our attention to the National Archives and Records Administration (NARA) in Washington D.C. This is an independent agency containing the federal records of the United States.
The guide to the archives (Matchette 1995) refers to the records of the American Expeditionary Forces as Record Group 120. Within the records of the 2nd Section of the General Staff (GHQ AEF), the Intelligence section, an aerial photographic collection is briefly described as “American, French, and some German aerial photographs and index maps relating to the Western Front, 1917-19 (16,291 items)” (NARA 2008).
Although the existence of this pictorial collection is described in Matchette (1995) and NARA (2008), few researchers are aware of its existence. The collection has been barely used for conflict archaeology or applications such as historical geography in large part because no finding aid or detailed description of the aerial photographs is at hand. Also, because they are listed within the records of the 2nd Section of the General Staff, the department responsible for military intelligences, one has to be familiar with the structure and function of aerial photography (gathering intelligences on the enemy) to be able to make the connection “aerial photography-intelligence – 2nd Section GHQ”. Even these sources proved very hard to find at the NARA, since their exact location could not be derived from Matchette (1995) or the online guide to the NARA. The aerial photographs finally came to surface at the cartographic department at the College Park branch of NARA.
Record Group 120: Aerial photos American Expeditionary Forces
The aerial photos of the American Expeditionary Forces are divided into 124 box files. A concise index to these box files is available as an addition to the preliminary inventory of the cartographic records of the AEF (Burch 1966). In NARA (2008) the collection is still described as 16,291 items.
The collection only contains printed aerial photographs, often measuring 18 x 24 centimetres. The NARA aerial photographs can be divided into four parts. The first part is all the miscellanea boxes containing various maps, aerial photographs and even ground photographs (Boxes 1-6). A second part contains American aerial photographs taken in 1918 (Boxes 7-25). The next group comprises aerial photos from 1919 of the American occupied territories in Germany (Boxes 26-68), but these boxes contain many duplicates (Boxes 37-68). The final box files only contain French aerial photographs (Boxes 69-124) of escadrilles attached to French army corps.
If we compare the number of boxes, we can conclude the American aerial photographs take up less than half of the collection. Only 30 boxes are unique aerial photos taken by the American Air Service. The vast majority of the images are of French origin (55 boxes).
The photos are first arranged by nationality. A further subdividing is based on the American Army Corps or French Corps d’Armée for which the photographs were produced. Subsequent arrangements sort the photographs by squadron or escadrille and finally the photographs are set in order by their original serial number.
Many of the American photographs are accompanied by a series of so-called “Reconnaissance Maps” which outline the location of individual photographs. Unfortunately these index maps are not complete. Boxes 7-19 and 22-23 are complete but Boxes 21, 24 and 25-35 have only partial coverage.
A difference in the nomenclature of the reconnaissance maps can be observed. Some mention “Reconnaissance Maps of 1st Army”, others “Army Corps”. This gives a first indication of the area in which the aerial photographs were taken. Aerial photographs taken for an army corps (military organisation consisting of several divisions), will be taken relatively close to the front line because they have a rather limited tactical horizon. Aerial photography in service for an army (several army corps) (Anon. 1962), mostly took place during long-range reconnaissance missions. Most aerial photography found at the NARA is related to Army Corps aerial photography and has a focus on the front line and the immediate hinterland.
The reconnaissance maps contain the plotted contours of the aerial photographs which were taken during a single flight (see for instance figure 2). Each of these squares is numbered so it corresponds with the World War One serial number of the images and the maps are named after the squadron which undertook the photo-reconnaissance mission. Additionally the photographed region, date, height, time, and name of pilot and observer are reproduced on most of the index maps. On some maps, the centre coordinates of the photographs are represented in the French Lambert coordinates.
No form of index is available for the French aerial photographs therefore we know very little about this part of the collection. However, the large quantities of French aerial photographs is easy to explain: some French escadrilles were assigned to the American Army Corps or Army observation groups (Anon. 1962) and a close co-operation existed between the Allied air services.
All 1918 coverage of the American aerial photographs is restricted to France, and more specific areas involving American troops, such as the Second battle of the Marne, the Battle of Saint-Mihiel and the Meuse-Argonne campaign (Toulmin 1927). Aerial coverage by American squadrons becomes available no earlier than April 1918. For some areas photographs are available up to the last days of the war in November 1918.
Additionally, frequent aerial photographs from 1919 are at hand, some depicting the aftermath of the war in France. Apparently in 1919 orders were still given to photograph the abandoned principal German positions on the American battlefields, the explanation for which can vary. It is possibly connected to the writing of the official war histories; other hypothesises are war damage assessment or conducting training flights with newly arrived pilots with no war experience.
Most of the post-war coverage was related to the Allied occupation of the German Rhineland, the principal points of interest being watercourses and connecting roads. Some rare photographs shed light on the photographers’ cultural interests as numerous chateaus and castle ruins were also documented.
It must be clear that this collection is under no circumstances to be considered as the complete archive of American aerial photographs taken between 1918 and 1919. Only a portion of photographs survived but the selection criteria are once more unknown. According to a leading officer in the American Air Service, 32,345 glass-plate negatives were exposed during the field campaigns (Toulmin 1927).
In order to have an understanding of the collection’s distribution, similar to the study and analysis of the other archives or museums, a GIS research was initiated. All available 461 reconnaissance maps were reproduced at the National Archives. Although not all the aerial photographs are accompanied by these index maps, it is believed they give a basic idea of the distribution of at least part of the collection. The reconnaissance maps were processed in GIS and Google Earth.
The total of located aerial photographs amounts to 7,267. An initial small cluster of 171 photographs is situated 30 kilometres east of Soissons (Cluster A). Clusters B and C (5,847 aerial photographs) are significantly larger and are situated further to the east, largely between Vouziers and Metz. Cluster D, consisting of 551 aerial photographs, is situated in the Rhineland-Palatinate in Germany, some 100 kilometres to the north-east of clusters B and C. Several flights were conducted to photograph the German-Luxemburg border and the major roads and rivers in the area. The centre of the final group of 698 aerial photographs (Cluster E) is situated at the confluence of the Rhine and the Moselle. From this area, reconnaissance flights photographed both rivers, Koblenz and also the major roads in the vicinity.
A visualisation of the 5,376 photographs from 1918 meets the expectations because only photographs of the first three clusters are represented. The dates of the photographs range between 25 April and November 1918. Cluster A consists of photographs taken by the 6th photo section of 88th Squadron between 10August and 31 October 1918. These photographs are related to actions of the American Expeditionary Forces during the Second battle of the Marne. Chronologically, the photographs of Cluster C are the next group, which were taken to support the Battle of Saint-Mihiel (11-19 September). The majority of the photographs dates to the months before the battle and were used to map the German defences. Cluster B contains aerial photographs taken during the Meuse-Argonne offensive (26 September-11 November).
The analysis of 1,891 of the post-war (1919) aerial photographs is more surprising . It was expected that each of the post-war photographs would be located in the US-occupied territories in Germany. A group of 642 aerial photographs was however taken between Vouziers and Verdun, photographed by the 24th Squadron, 1st Army. The localisation of the photographs and their dating in 1919 is confirmed by a historic document showing the progress of work on the photographic assignment of the First Army Observation Group.
The objectives which needed to be photographed correspond with the battlefield of the Meuse-Argonne offensive. Unfortunately no specific need for this assignment was stated. In our opinion these photographs can be related to the documentation of the destroyed villages at the battlefield. Alternatively, there may have been a necessity for photographs of the battlefield from the viewpoint of the historiography of the AEF. Examples are known where British and French aerial photographs were ordered in the post-war period to document areas where American units had fought but for which no own aerial coverage was available (Maurer 1978).
The remaining 1,249 aerial photographs were taken by photo sections of four different squadrons and are all located in the Rhineland. The availability of American aerial photographs for this area is easy to explain. As part of the 1919 Versailles Treaty, the Rhineland became a demilitarised zone and was occupied by Allied troops. A striking feature is the large ratio of oblique to vertical photographs and also many cultural subjects such as castles, fortresses and ruins on the photographs. These photographs may have been taken for training purposes.
The following map shows the distribution of all located WW1 NARA aerial photographs:
Although RG 120 is not the most sizeable collection, the aerial photographs still have special value. Firstly, it is the only know systematic collection of American military aerial photographs of the period. Secondly the structure of the collection allows the retrieval of individual aerial photographs by means of the attached reconnaissance maps and because the photographs are stored in the order they appear on the reconnaissance maps, this archive has a huge potential for stereoscopic research of overlapping images. This is the easiest archive in which to find these images. An additional benefit is that photographs on the same reconnaissance map are of the same date and the coverage joins well, making it possible to study an entire landscape at a specific moment.
Unfortunately, as happens to be the case with most of studied collections, this collection is certainly not complete. Sources mention more than 32,000 exposed plates between 1 July and 11 November (Toulmin 1927) which contrasts sharply with the 7,267 aerial photographs discovered at the NARA.
Because of the lack of an inventory or classification of the boxes with the French aerial photographs it was not possible to include them in the detailed GIS overview. However most of the boxes were inspected and many of the aerial photographs were examined This revealed that some of the French photographs are also located in the Meuse-Argonne area. Additional boxes cover Lorraine, Alsace, Luxemburg and Rhineland. It was also found that the French photographs are filed according their original serial number.
Due to the localisation of the photographs in the GIS it was possible to gain more insight into the distribution per year of the American aerial photographs stored at NARA.
Anon. (1962). "The Eyes of the Army: The Observation Corps." Cross & Cockade 3(71): 71-88.
Burch, F. (1966). Preliminary Inventory of the Cartographic Records of the American Expeditionary Forces, 1917-21. Washington DC, The National Archives.
Dubinin, M. (2007). "KML2Shape." Retrieved 2-06-2008, from http://arcscripts.esri.com/details.asp?dbid=15175.
Finnegan, T. J. (2006). Shooting the Front. Allied Aerial Reconnaissance and Photographic Interpretation on the Western Front - World War I. Washington DC, National Defence Intelligence College Press.
Matchette, R. (1995). Guide to Federal Records in the National Archives of the United States. Washington DC, National Archives and Records Administration.
Maurer, M. (1978). U.S. Air Service in World War I. Vol 1. Washington DC, Government Printing Office.
NARA (2007). RG 120: Records of the American Expeditionary Force. Aerial Photographs. Washington DC, NARA: 1.
NARA (2008). "Web Version Based on Guide to Federal Records in the National Archives of the United States. Compiled by Robert B. Matchette et al. Washington, DC: National Archives and Records Administration." Retrieved 6-02-2008, from http://www.archives.gov/research/guide-fed-records/groups/120.html.
Toulmin, H. (1927). Air Service, American Expeditionary Force 1918. Nashville, The Battery Press.