The Canadian National Steamships Company had its beginnings in 1908 when its predecessor, the Grand Trunk Pacific Railway (GTP), bought MacKenzie Brothers Steamships Ltd. in order to provide tugboat and barge services from Vancouver to Prince Rupert. Soon, the GTP also began providing shipping services to Victoria, Seattle, the Queen Charlotte Islands, and Skagway, Alaska. On February 26, 1925, the GTP was taken over by the Dominion Government, and it became part of the Canadian National Railway (CNR).
The Canadian National Steamships Act of 1927 united all steamship companies allied with the Canadian National Railway, and these companies then ran under the title of the Canadian National Steamships Company (CNSS). In addition to the GTP’s steamship company, the CNSS now included the Canadian National (West Indies) Ltd., and in 1928, it also included the Canadian Government Merchant Marine Ltd. The CNSS ran routes to Vancouver, Victoria, Seattle, the Queen Charlotte Islands, Skagway, Montreal, Halifax, the West Indies, and Australia. The Australia routes were short-lived; in 1936 the CNSS transferred the routes to Port Line, Ellerman & Company, and to the New Zealand Shipping Company. In 1945, the CNSS also took over the operation of the barge and ferry services that MacKenzie and Mann began in in 1916. At various times, these services ran between the mainland and Vancouver Island, and to Prince Rupert, Kelowna, Penticton, Summerland, and Lake Naramata.
In addition to the tugboats and barges that the CNSS operated, they acquired many luxury ships. On their West Coast routes, for example, they sailed the sister ships Prince Henry, Prince David, and Prince Robert. Notably, in 1939, the Prince Robert was used as the “royal yacht” to transport King George VI and Queen Elizabeth on their trip from Victoria to Vancouver. From their East Coast ports, the CNSS sailed five luxury ships known as the “Lady Boats.” While the luxury passenger ships were popular among many, their success was limited by the Great Depression. Then, during World War II, many of them were used for the war effort. For example, the Prince Robert was converted into an auxiliary cruiser by the Canadian Navy, and then became the first Canadian anti-aircraft cruiser. Additionally, the Lady Boat Lady Somers was converted into an auxiliary armed cruiser, and the Lady Nelson was converted into a hospital ship.
After World War II, Lady Rodney and Lady Nelson were the only two Lady Boats that had not been sunk. In 1946, they were used to transport war brides from Great Britain to Canada, and then in 1947 they were used once again as luxury passenger cruises to the West Indies. This service lasted until 1952, when the Lady Boats were sold. Similarly on the West Coast, the CNSS only had one remaining vessel after the war; the Prince Rupert continued to be used, and in 1946, it was the first Canadian ship equipped with radar. In 1948, the CNSS put a new Prince George into service, and in 1956, after the Prince Rupert was sold, the Prince George was the only vessel being operated by the CNSS. The Prince George had her last sailing in 1975, and she was sold in 1976.
In 1977, a branch of the CNSS became CN Marine. In 1986, CN Marine re-branded itself as Marine Atlantic. Today, Marine Atlantic runs ferry services between Newfoundland and Nova Scotia.