At the turn of the 20th century, the Canada Division main line was the busiest passenger route in Canada.

At the end of 1901, the Michigan Central Railroad ran seven passenger trains between Detroit and Buffalo. The Grand Trunk provided only four on its busiest route between Montreal and Toronto. By 1920, the Canada Division was also carrying more passengers per train mile than any other Canadian railway. For each passenger and mixed train mile operated, the Canada Southern Railway (CSR) handled 85 passengers, the Canadian Pacific 77, and the Grand Trunk Railway only 64. Measured in terms of passenger density and number of trains operated, the CSR remained Canada’s single busiest line through the 1950s.

What boomed were the main line passenger runs. Indicative of the growth, the St. Thomas Journal commented in early 1922 that the Wolverine had been operating two sections up to five days every week for the previous two years. It also noted the passage of an eighteen car passenger train pulled by two Pacific locomotives. The summer of 1923 found the Canada Division handling 2,300 through passengers per day.