[9] By the 1920s the port boasted two miles of quays, with warehouses, stationary and mobile cranes, and with railways along the entire length connected to the four rail systems serving the city.

The Commissioners ensured the channel was dredged and well marked, and also maintained a pilot station at Inishowen Head, and a roadstead at Moville, which was a port of call for transatlantic steamers carrying mail.

The outbreak of the Second World War, and the German campaign against Allied shipping, saw the establishment of a naval base, HMS Ferret on the Foyle, with the use of port facilities in the city, and the building of new quays at Lisahally, at the mouth of the river where it enters the lough.

Londonderry Port and the docks at Lisahally gave vital service to the Allies in the longest running campaign of the Second World War, the Battle of the Atlantic.

About a dozen boats came alongside for that official surrender, taken by Admiral Sir Max Horton in the presence of US, Canadian and Republic of Ireland commanders;[11] the other U-boats arrived over the next several weeks.

The cattle-holding pens that used to be near where the current British Telecom building stands were demolished along with the transit sheds in order to create a new road and car parking along the banks of the River Foyle.

[13] In recent years Londonderry Port and Harbour Commissioners have established a number of diversified trading divisions marketed under the "Foyle" brand: Lisahally Terminal has 440 metres (1,440 ft) of quay and can facilitate vessels up to 62,000 GT.

Most of the current Londonderry Port is in the townland of Lisahally (or Lissahawley), a toponym that may be derived from Irish Lios a' Chalaidh 'ringfort of the landing place'.

[14] The port has witnessed mass emigration of Irish and Scots-Irish people over the centuries to North America, Scotland, England and Australia.