These were the beginning of the idea of a future interconnected network, which would also develop in other nearby countries (Baden, Bavaria and Switzerland).

In 1840, Baden had begun the construction of its Rhine Valley Railway from Mannheim to Heidelberg, Bruchsal, Durlach and Karlsruhe, and later to Basel and Constance.

Baden wished to provide a rail connection through Pforzheim (which was an important industrial city) and also to keep transit traffic on the Rhine Valley Railway as long as possible.

Preliminary discussions between the two countries led in the late 1830s to a study of the Pforzheim route by a joint commission, which found it to be suitable for Baden but inappropriate for Württemberg.

Given the disagreement, the Württemberg railway law of 1843, which authorised the construction of its main lines, initially only stated that a connection should be made to the Baden network, without specifying a route.

The Württemberg Diet was inclined to agree to Baden's desire for the Pforzheim route, but only on condition that the Heilbronn–Wiesloch line should be built as well.

When negotiations recommenced in 1850, Württemberg had already completed other major lines (from Heilbronn to Stuttgart, Ulm and Lake Constance).

The railway was built under the direction of Karl Etzel, using standard gauge of 1,435 mm (4 ft 8+1⁄2 in), which had already become widely accepted in most European countries.

The British rail expert, Charles Vignoles recommended a junction with the Northern Railway in Tamm and the building a large viaduct at the Bissingen saw mill to reach Kleinglattbach and Illingen on a direct route.

These alignments had the advantages that they were relatively straightforward; their disadvantages was their need to run through difficult terrain with poor grades and the requirement of a high and long bridge over the Enz.

Karl Etzel proposed in 1845 the more northerly branch in Bietigheim, since the Enz valley was at its narrowest there and therefore a shorter and lower bridge was required than in the previous plans.

Etzel's ideas prevailed, and so the Enz valley viaduct was built at Bietigheimer, with a length of 287 metres and a height of 26 meters, the largest engineering works on the route and very expensive to build.

The town of Bruchsal initially opposed a plan to tunnel under the cemetery, since it was thought that it would disturb the peace of the dead.

It was then proposed to build a separate terminal station for the Württemberg railway before Bruchsal in the Saalbach valley, which would have avoided the cost of constructing the tunnel, amounting to 200,000 guilders.

Under a treaty of 1850, the line was operated for its full length, including in Baden, by the Royal Württemberg State Railways.

In conjunction with the Mühlacker–Bietigheim line, this provided a more direct link between Karlsruhe and Stuttgart, which became an important route for long-distance services.

With the construction of the Kraichgau railway, the Bretten Station, which had previously been in close proximity to the city centre, was moved to the south-western outskirts.

The original stations along the line were in Mühlacker, Maulbronn and Bretten, with halts in Großsachsenheim (now Sachsenheim), Sersheim, Illingen, Gondelsheim and Heidelsheim.

During 1904, the Vaihingen–Enzweihingen line (called the Vaihinger Stadtbahn prior to the suspension of its operations in 2002) opened from Sersheim-Vaihingen station, which was situated some distance from both Vaihingen and Sersheim.

The narrow and steep curves (with grades of about 1.0%) between the station and the cemetery tunnel had over time become an obstacle for the heavier trains now running.

In 1914, before the start of World War I, there were nine daily long-distance trains operating on the Bruchsal–Mühlacker–Bietigheim section, connecting western Germany and the Netherlands on one hand and Bavaria and Austria on the other.

In the course of World War II, the line played an important role, particularly in the transportation of coal from the Saar to southern Germany and Austria.

After that stations and trains were more and more affected by bombing and strafing, causing many deaths and injuries and great property damage.

To relieve congestion on the Western Railway, DB had planned a high-speed line between Mannheim and Stuttgart since the late 1960s.

As the existing station of Vaihingen (Enz) Nord was poorly laid out and was distant from the town it served, a new seven kilometre-long section was built to the west of the old line.

This meant that traffic on the Western Railway fell sharply as it was now used almost exclusively for regional passenger and freight services.

To increase its attractiveness, the Albtal-Verkehrs-Gesellschaft (Alb Valley transport company, AVG), the operator of the Karlsruhe Stadtbahn, extended services over the Western Railway to Bretten in 1992.

Also on 30 May 1999, AVG extended line S5, which previously ended in Pforzheim, to Mühlacker, continuing on the Western Railway to Bietigheim-Bissingen, which provided a transfer-free connection to the centre of Karlsruhe.