1919 2nd Engineers Cyanotype Map of Ehrenbreitstein Fortress, Germany

Headquarters of the U.S. Occupation of the Rhineland after World War I.

This is a scarce, curious 1919 cyanotype map of the Ehrenbreitstein Fortress, along the Rhine River in Germany, produced by the U.S. Army's 2nd Engineers. Prepared just months after the Armistice that ended World War I (1914 - 1918), the map provides fantastic detail on the fortress, which served as the headquarters of the American Occupation of the Rhineland.

A Closer Look

Oriented towards the west (facing the Rhine), this map covers Ehrenbreitstein Fortress, situated along the east bank of the Rhine River where it meets the Moselle River, just outside of Koblenz. The various internal subsections, such as bastions, batteries, and strongpoints, are labeled with numbers corresponding to an index at the bottom-left. Roads, paths, and symbols for other features are explained in a legend, also at the bottom-left. Some recent additions to the fort are recorded as well, such as a motor school and balloon hangar, as well as a Y.M.C.A. Theater.

Ehrenbreitstein Fortress

Covering more than 10 hectares, the large Ehrenbreitstein Fortress was the cornerstone of a Prussian-built system of fortifications around Koblenz, constructed in the decades after the Napoleonic Wars (1803 - 1815). Built on a hill overlooking the Rhine, the site boasted centuries of fortification from at least the 10th century BCE. The structure seen here represented the state of the art in military defenses of the mid-19th century, the last period before such fortifications were made redundant by modern rifled artillery. Ironically, despite its imposing structure, the fortress seen here was never attacked or besieged, instead being surrendered to and occupied by Allied (American) troops. At the end of World War I (1914 - 1918), the original plan for occupation called for the fortress to be dismantled, but the American General acting as Military Governor of the region, Henry Tureman Allen (1859 - 1930), decided to preserve it due to its historical value. Instead, the fort became the headquarters of the U.S. Army's Occupation of the Rhineland until it was handed over to French forces in early 1923.

Cyanotype: Why so Blue?

Cyanotype is a photo-reprographic technique developed in 1842 by the British astronomer John Herschel (1792 - 1871). Sometimes called a 'sunprint', the technique employs a solution of ferric ammonium citrate and potassium ferricyanide painted on white paper or cloth, which then reacts when exposed to sunlight to dye the object a brilliant blue. Areas blocked from ultraviolet exposure remain undyed and white. Herschel developed the technique to reproduce his astronomical notes, but others quickly realized that any object capable of blocking light could be used to create a cyanotype image quickly and easily. By the late 19th century, the process became popular with designers, military, architects, and engineers (blueprints), who used the cheap and effective technique to quickly and exactly reproduce images in the field. Cyanotyping is limited in that only a single copy can be made at one time, so it was only practical for short-term field work. It is also of note that cyanotypes remain extremely reactive to light and, over time, fade or degrade, making them extremely ephemeral. The process fell out of fashion in most places by the 1920s but remains in use in some parts of the world, such as India and Nepal, to this day.

Publication History and Census

This map was prepared by the U.S. Army's 2nd Engineer Regiment, of the 2nd Division in the First Corps of the American Expeditionary Forces. We have been unable to locate any other examples of this map in institutional collections or on the market.

Condition

Very good. Light wear along original fold lines.