Its all in the Cards. A revolution in information technology during the 1920s

Index cards and card-file indices have shaped data collection and management in modern societies throughout the 20th century. They turned into a key innovation during the 1920s; massive card-based data engines became omnipresent during the first half of the century and grew into integral parts of data management systems with vastly increased efficiency. The power of card-file systems was used in business and manufacturing to administer populations, raise armies, and organize mass murder, genocide, and the Holocaust.

In Germany, card-based knowledge machines had their breakthrough – in business and administration – during the interwar years. They soon became a most powerful tool to record and track people and things and for data-driven decision-making and process control on a hitherto unseen level.

What happened during the 1920s when the “Kartei” turned into an ubicuos tool of knowledge? Card-file systems did not appear out of the blue, of course. Library catalogs had been around for centuries. Still, they were seen as relatively simple applications even though the more complex “Sachkatalog”, which organized books not by names but by subject classifications, proliferated.

The police had also been thinking about index systems as they modernized the “Erkennungsdienst” (or “police records department”). During the 1920s, police officials in Germany discussed science-based innovations: identification through fingerprints, the introduction of typewriters and photography, and using card-file indices in their everyday work – referring back to the legendary index on Berlin’s inhabitants kept in the police headquarters of the capital which originated in 1836 and boasted 14 million index cards – allegedly –, as Franz Feldhaus pointed out in “Police and Technology” in 1926.

Data-flows in production managed with card-file systems as proposed by Grupp in 1914..

But the main drive to make the index an everyday tool to organize knowledge in practice gained momentum in the business world first. In 1914, Werner Grull argued in his handbook on the organization of production facilities that interlinked card indices should be introduced to all departments to organize information from production to sales, from personnel to advertising.

He also mentioned that a new class of office workers would emerge: the card-file operators, the “Karteiführer” was born, the information management specialist of the pre-digital age, and his boss, the “Karteibeamte” as head of all the indices in the company. In Grull’s mind, the index was a fast and efficient tool for handling a multidimensional organization of data by topic and time, markers, color codes, etc., with the entirety of the indices being a living data double of all processes in a company.

During the last years before the war, many publications, some by academics and some by practitioners, argued for modernization, progress, efficiency, and ultimately success through total datafication. Everything needed to be on an index card, and everyone required indexes, and new index card and index system designs emerged in a steady flow. Handbook articles taught card-file design. A few years later, suppliers offered ready-to-use “Karteimöbel” and custom-designed cards for every conceivable purpose.

The Hinze-System desk with integrated card-file drawers advertised in 1920.

But the innovation faced an uphill battle. W. Porstmann published an essay in “Prometheus. The weekly Journal on progress in the trade, industry and science” in 1920. He railed against the dismissal of index cards as “stacks of paper” and thus their description as the primitive sibling of the book. In his mind, the enormous flexibility and speed of organizing material by cards would be a game changer on many levels. He thought that only the card-file index could match the complexity of modern life and production and keep pace with a world that changed faster and faster. The book and even the” American Journal”-format in bookkeeping were yesterday’s tools to the pionieer of the card-based knowledge machine.

The age of the card-file index had begun. Of course, Mr. Porstmann, of Hinze & Co., was himself in the business of promoting the Hinze card-file system for bookkeeping and an integrated workplace tailored to a multidimensional tool for information management.

But of course, this was hardly new. What publications advocated and what businesses adopted at the time was the translation of Taylor’s system of business organization. The economist Rudolf Seubert delivered one of the more detailed German-language descriptions of how Taylor Manufacturing in Philadelphia used index-file systems in 1920 to his readership.

Add for a card-file system printed in 1919.

But the Germans, of course, would overdo it a bit. As documented in a growing number of handbooks and ready-to-go card-file systems available during the 1920s, their drive for “Karteien” surpassed what Taylor had in mind by far.  

One part of this drive was practical considerations; another was an intellectual debate.

Some authors looked back, like Carl Breuer in 1921, who referred to an early modern “knowledge machine” he compared to the first steam engines and argued that the streamlined and simplified grandchildren of these machines were now unleashing their full potential in the hands of everyone. The same would happen to the new information technology.

Some authors looked ahead, like Professor Friedrich Kuntze from Berlin University, who published his monograph “Technik der geistigen Arbeit” in 1923. He adapted multidimensional business card-file systems, like those discussed above, to academic purposes, arguing that the card-file systems introduced the latest business innovations to practical research in the humanities. As a philosopher, he developed a Dewey classification system combined with a 10-dimensional index card system to organize the entirety of philosophical knowledge.

While these debates and experiments went on in Germany, the state also discovered the card-file system. And not before long, the introduction of the tool to all branches of the administration became the most significant consequence of this modernization drive. At the end of the 1920s citizen registers, foreigner registers, taxpayer registers, and police registers were all converted to card-file based systems. During the Nazi period tracking and policing populations from labor extraction to organizing the German war machine, to creating a “Volksgemeinschaft” and organizing the Holocaust was all based on massive decentralized and centralized card systems at some point. The Nazi Party organized its members based on a complex series of index card systems as early as the 1920s.

The card-file register of NSDAP Members in Germany’s Federal Archives.

Organizations and individuals began to learn how to use this tool enthusiastically during the 1920s, the German state adopted the tool as a backbone of its information management, Nazi Germany based its rule on modern information technology.

When the Allies began to study the structure of German administration during the war, they were shocked by the number of indexes, their dimensions, and the efficiency of datafication combined with the ability of bureaucracies to base almost “real-time” decisions on the use of index card systems.

Many of the index card systems survived 1945. They were continued until they transitioned into digital form in the late 1970s when databases were built like index card systems, and a tool that had dominated large-scale data processing for half a century structured the early stages of the digital age.   

This essay grew out of a broader research project at NGHM focussed on card-file based information storage in Germany from the 1920s to the 1980s based on digital data models of the “Gestapokartei” and the “Ausländermeldekartei” for the city of Osnabrück, both of which have been preserved in the State Archives of Lower Saxony; an earlier version was presented at the workshop “Little tools of knowledge“, organized by Prof. Vera Keller at the University of Oregon in May 2022.

See also:

  • Rass, Christoph, Sebastian Bondzio und Wiebke Wellnitz: Machtkampf. Raumbezogene Strategien von NSDAP und KPD in Osnabrück (1928-1933), in: Osnabrücker Mitteilungen 127 (2022).
  • Rass, Christoph, Henning Borggräfe und Lukas Hennies: GEOINFORMATIONSSYSTEME IN DER HISTORISCHEN FORSCHUNG. Praxisbeispiele aus der Untersuchung von Flucht, Verfolgung und Migration in den 1930er- bis 1950er-Jahren, in: Zeithistorische Forschungen (1/2022), S. 148-169.
  • Rass, Christoph, Sebastian Bondzio: Big Data und die Digitalisierung von Geschichte und Geschichtswissenschaft, in: Jahresbericht der Stiftung Niedersächsische Gedenkstätten 2021, Celle 2022, S. 16-21. 
  • Rass, Christoph, Sebastian Huhn, Sebastian Bonzido u.a.: Die Osnabrücker Ausländermeldekartei 1930-1980. Potenziale als Quelle der Stadt- und Migrationsgeschichte, in: Osnabrücker Mitteilungen (126/2021), S. 137-194.
  • Rass, Christoph, Sebastian Bondzio: Next Stop Big Data? Erfahrungen mit der Digitalisierung von Geschichte und Geschichtswissenschaft, in: Vergangenheit analysieren – Zukunft gestalten, herausgegeben von Paul Thomes und Tobias Dewes (Aachener Studien zur Wirtschafts- Sozial- und Technologiegeschichte Band 20), Aachen 2020.
  • Rass, Christoph, Sebastian Bondzio: Allmächtig, allwissend und allgegenwärtig? Die Osnabrücker Gestapo-Kartei als Massendatenspeicher und Weltmodell, in: Osnabrücker Mitteilungen (124/2019).