The main initiator of the merger were the Zürich-based businessman Alfred Escher, who previously headed the Zürich-Lake Constance Railway, and economist Bruno Hildebrand.

The NOB endeavored to establish connections with foreign countries to generate freight traffic.

Thus it became a direct competitor of the United Swiss Railways (Vereinigte Schweizerbahnen; VSB) based in St. Gallen.

The arrival of the railway caused the village of Romanshorn to grow into one of the most important transport hubs in eastern Switzerland.

This led the NOB to expand the railway facilities and to construct the largest of the ports on Lake Constance (measured by area), which required the shore to be raised.

The rest of the line to Aarau was opened on 15 May 1858 where the network of NOB connected with the network of the Swiss Central Railway (Schweizerische Centralbahn; SCB) at Wöschnau on the Aargau-Solothurn canton border, meaning that Zürich was now connected with Basel.

On 18 August 1859, the NOB was able to complete a direct connection with a foreign country with the opening of the Turgi–Waldshut line.

Freight transport was NOB's most important business segment, which initially enjoyed good returns.

After the Schweizerische Ostwestbahn (Swiss East West Railway, OWB), which had been founded in 1861, had become bankrupt in an attempt to build a line from La Neuveville via Bern and Lucerne to Zürich, the NOB together with the cantons of Zürich, Zug and Lucerne, took over part of its line and completed it as the Zürich–Zug–Lucerne Railway (ZZL), which was finished on 1 June 1864.

In addition, the NOB under the new CEO Friedrich Peyer im Hof, tried to eliminate the competition in advance by an accelerated expansion of its own network.

On 2 March 1877, the NOB requested that the Federal Council release it from its obligations to build railways.

On 14 February 1878, the Federal Assembly confirmed an agreement that the construction obligations would be maintained, but would be deferred until the completion of the NOB's financial restructuring.

On 25 October 1887, the Federal Council instructed the NOB to begin construction of the Lake Zurich right bank line.

A financial group led by Adolf Guyer was able to secure a majority of votes at a general meeting of the company, allowing it to select the board of directors and replace it with people who would cooperate with its interests.

[3] An NOB passenger train hit a group of Central Railway workers, which had been busy with track work, at the southern exit from Gütsch tunnel near Lucerne on 30 May 1898.

The industrial action at the NOB contributed to the holding of a referendum in 1898, which approved the nationalisation of the largest private railways.

The NOB started operating shipping services on Lake Constance with the Thurgau and the Stadt Zürich in 1855.

The NOB merged with the Schweizerischen Dampfboot-Aktiengesellschaft für den Rhein und Bodensee (Swiss Steamboat Corporation for the Rhine and Lake Constance) on 1 January 1857.

In order to avoid the reloading of goods, the Bavarian and the Württemberg steamship administration together with the NOB decided in 1867 to transport railway wagons by train ferry.

In 1887, the NOB put the newly built saloon steamer Helvetia III into service, which caused a sensation with its clipper bow and bowsprit.

In 1902, with the nationalisation of the NOB the entire shipping company was transferred to the Swiss Federal Railways (SBB).

Shortly before the commissioning of the Lake Zürich left bank railway (Linksufrige Zürichseebahn), the NOB took over the entire shipping fleet in 1875.

When the Zürich–Meilen–Rapperswil railway started operation in 1894, the existing fleet of six ships: Helvetia, Concordia, Lukmanier, St. Gotthard, Taube and Schwalbe was reduced.