Until after World War II, compartment cars, a type of car that is little known today, dominated passenger transport. The first compartment cars were derived from the body of a stagecoach; several coach bodies were placed one behind the other on a railway chassis. The compartment doors led directly outside, which allowed passengers to get on and off quickly. The Prussian State Railway in particular used various types of compartment cars, initially with two axles, later with three axles; from 1890, four-axle cars were added for express trains. From 1895, the first cars were built according to sample sheets; from 1900, 700 longer cars followed according to D.1.21 to D.I.23.
