of the sections Eutingen–Tuttlingen and Hattingen–Singen, while the sections Eutingen–Stuttgart and Tuttlingen–Hattingen were still missing. On 22 March 1873, the state of Württemberg legislated the creation of a railway between Stuttgart, via Herrenberg and Eutingen, to Freudenstadt, closing the gap between Stuttgart and Eutingen. In the discussions prior to the passage of this law, the term Gäubahn was used for the first time to label the section Stuttgart-Freudenstadt, and the term would later become the name for the entire line between Stuttgart and Singen. In November of the same year, construction on the technically challenging railway began in Stuttgart, led by the Württemberg engineer Georg Morlok. The track routing was quite complex, having to conquer steep grades and incorporating many tunnels. Much of the labor recruited by Morlok came from Italy. Construction went well: During the winter 1877/78, the line had already reached Herrenberg. On 20 August 1879, after a trial run from Stuttgart to Freudenstadt, the Royal Württemberg State Railways officially opened this section on 2 September 1879, in the presence of chief engineer Georg Morlok, the president of Württemberg Hermann von Mittnacht, the mayor of Stuttgart Gottlob Friedrich von Hack, and many other dignitaries. The construction of this section shortened the distance between Stuttgart via Horb and Tuttlingen to Immendingen by 35 kilometers, and cut the trip time by 1 to 2 hours. From regional to long-distance railway (1879–1919) The Gäubahn Stuttgart–Tuttlingen–Immendingen was primarily of regional importance at this time. The terminus of all long-distance travel was Immendingen. However, by the end of the 19th century trip times were becoming quite a bit shorter, to the point where the trip between Tuttlingen and Stuttgart had been cut down to only 3 hours in 1897, 4 to 5 hours less than in the 1870s. Starting in 1900, 3 daily express long-distance trains traversed the line, some of the time from Stuttgart via Immendingen all the way to Zurich. This trip did still require that passengers change trains in Immendingen. Around the turn of the century, the Royal Württemberg State Railways mostly used the steam locomotives of the class Württemberg AD for their express service, which were in turn replaced by the class Württemberg C during World War I. The class Württemberg T 5 was used for regional service. The 9th of April 1917 saw what was probably the most famous passenger on this line, when the leader of the