April 1837, becoming the third German railway to be built. The line was completed through to Dresden on 7 April 1839. With a total route length of , this was also the first German trunk or long-distance railway and the first exclusively steam-powered railway in Germany. Its route also included the first German railway tunnel. On 29 June 1839, the first section of the Magdeburg-Leipzig Railway, from Magdeburg to Schönebeck was opened. After being extended to Halle and Leipzig in 1840 it became the first international main line and had a route length of . Between 1839 and 1843, the Rhenish Railway was built from Cologne to the border station of Herbesthal, with its connection to Antwerp. The line was opened on 15 October 1843 and was the first railway line that crossed an external border of the German Confederation. On 12 September 1840, the Grand Duchy of Baden opened a state railway: the route from Mannheim to Heidelberg and the first section of the Baden Main Line from Mannheim to Basle, which reached Freiburg im Breisgau on 1 August 1845, and which was completed in 1855. Unlike all the surrounding railways, Baden used a broad gauge of 1600 mm until 1854/55. On 12 September 1841, the Berlin-Anhalt Railway Company began working the route from the Anhalter Bahnhof in Berlin to Köthen (Anhalt), where the line met the Berlin-Potsdam-Magdeburg Railway. As a result, Köthen became the first railway hub in Germany. With the opening of the Berlin-Frankfurt Railway on 31 October 1842 from Berlin's Silesian station to Frankfurt (Oder) the now loosely connected German railway network now had a total length of just under 1,000 km. On 22 October 1843, the Kreuzbahn ("cross railway") was opened from Hanover to Lehrte, the first line operated by the Royal Hanoverian State Railways. Lehrte became an important railway hub, with routes to Berlin, Cologne, Hildesheim and Harburg in front of the gates of Hamburg. The first section of the Cologne-Minden Railway, from Deutz to Düsseldorf, was opened on 20 December 1845; the second section to Duisburg followed on 9 February 1846. The line was extended the following year, reaching Hamm via Dortmund on 15 May. On 15 October 1847, the entire line to Minden was completed, initially just single-tracked. On the same day the line from Hanover to Minden was opened by the Royal Hanoverian State Railways. On 1 September 1846, the last