[The cathedral, side, Cologne, the Rhine, Germany]

Photochrome is a process for producing colorized images from black-and-white photographic negatives via the direct photographic transfer of a negative onto lithographic printing plates. The process was invented in the 1880s and was most popular in the 1890s.

The Detroit Publishing Company was started by publisher William A. Livingstone and photographer Edwin H. Husher. ln 1905 that the company called itself the Detroit Publishing Company. The best-known photographer for the company was William Henry Jackson, who joined the company in 1897. The company acquired exclusive rights to use a form of photography processing called Photochrom. Photochrom allowed for the company to mass-market postcards and other materials in color. We at GetArchive are admirers of their exceptional high-resolution scans of glass negatives collection from the Library of Congress. By the time of World War I, the company faced declining sales both due to the war economy and the competition from cheaper, more advanced printing methods. The company declared bankruptcy in 1924 and was liquidated in 1932.

In 50 AD, the Romans founded Colonia Claudia Ara Agrippinensium (Cologne) on the river Rhine and the city became the provincial capital of Germania Inferior in 85 AD and one of the most important trade and production centers in the Roman Empire until it was occupied by the Franks in 462. By the end of the 12th century, the Archbishop of Cologne was one of the seven electors of the Holy Roman Emperor. In 1288, Cologne gained its independence from the archbishops and became a Free City within the Holy Roman Empire. The Free Imperial City of Cologne must not be confused with the Electorate of Cologne which was a state of its own within the Holy Roman Empire. Cologne's location at the intersection of the major trade routes between east and west as well as the south-north was the basis of Cologne's growth. By 1300 the city population exceeded 50,000. Cologne lost its status as a free city when all the territories of the Holy Roman Empire on the left bank of the Rhine were incorporated into the French Republic and Napoleon's Empire. The Cologne Cathedral, started in 1248, abandoned in 1560, was eventually finished in 1880 not just as a place of worship but also as a German national monument celebrating the newly founded German empire and the continuity of the German nation since the Middle Ages. By World War I, Cologne had grown to 700,000 inhabitants. During World War II, the Allies dropped 44,923 tons of bombs on the city, destroying 61% of buildings, causing 20,000 civilian casualties and wiped out the central part of the city. In 1945 architect and urban planner Rudolf Schwarz called Cologne the "world's greatest heap of rubble". The reconstruction lasted until the 1990s.