The Deutscher Eisenbahn-Verein (German Railway Society) or DEV was founded in November 1964 as the Deutscher Kleinbahn-Verein (""). Its purpose was the preservation of a working branch line with all its installations as a living open-air museum. The term Kleinbahn was primarily a Prussian concept that referred to light branch lines with lower traffic demands and of more lightweight construction than main lines or normal branch lines, hence the Kleinbahnen were mainly found in northern Germany.