The first real need for a permanent link from the mainland to Cape Breton Island at the Strait of Canso was realized when the Canadian National Railways added Cape Breton to its trans-continental system. The first mode of transportation across the Strait to Cape Breton was a steam powered ferry and a train barge known as the S.S. Mulgrave. The ferry would cross towing a barge which carried railway cars and heavy freight. However, large volumes of traffic and dangers associated with the heavy loads for a small ferry supported the fact the S.S. Mulgrave was inadequate to serve as a connection between mainland Nova Scotia and Cape Breton Island.

In 1901, a new ferry was purchased by the CNR. The new ferry was called the "Scotia I" and was a larger vessel that could handle a larger volume of traffic and heavier loads. The Scotia I however seemed only to be a quick fix for the S.S. Mulgrave and thus efforts to establish a fixed link or crossing continued on.

In the early 1900’s Cape Breton was beginning to expand with increases in coal production, steel plants in Sydney and iron and coal mines developed in the Sydney industrial area. Another prosperous coal mine developed in the town of Inverness which had a direct railway from Point Tupper, thus having freight opportunities form mainland Nova Scotia. Another railway link from Point Tupper to St. Peters was finalized in 1903. The railway system was flourishing in Cape Breton Island thus leading to tremendous mining opportunities and large impacts on the economy of the island. The need for a connection between Cape Breton Island and mainland Nova Scotia was growing in importance.

With the beginning of the second world war, more and more ships and vehicles passed through the strait of Canso. The congestion problem caused delays of up to three hours for vehicles to reach Cape Breton Island from mainland Nova Scotia. The need for a permanent link to Cape Breton that would free up the congestion problems became mandatory.

Meanwhile, another major impact for the creation of the causeway was occurring in what is known as the province of Newfoundland. On December 11, 1948, Newfoundland had been granted confederation status and thus more and more traffic, businesses and citizens were relocating to that province.

The causeway was proposed to cost $22,760,000 in total including a navigation lock and bridge on the Cape Breton side which would allow ships with a 30 foot draught to pass through the strait