Champlain and St. Lawrence Railroad

The C&SL was financed by Montreal entrepreneur and brewery owner, John Molson. It was intended as a portage road to connect the St. Lawrence River valley with Lake Champlain, cutting time from the trip between Montreal and New York. Construction began in January, 1835 when surveyors determined the line would run from St. John on the Richelieu River to the nearest point on the St. Lawrence at La Prairie, across the river from Montreal.

Throughout 1835 the grading, fencing, masonry and bridge work were completed, as well as stations and wharves at Laprairie and St. John. Orders were also placed for a locomotive, which was to be built in Newcastle upon Tyne, as well as four passenger cars, which were to be built in the United States. Several freight cars were also built in Montreal.

The 16-mile (26 km) line was built as a 4 ft 8+1⁄2 in (1,435 mm) standard gauge railway, with rails consisting of 6-inch (152 mm) pine logs (squared off) which were joined by iron splice plates and bolts laid across wood cross-ties. The pine rails were protected by iron straps spiked to the upper surface. These rails remained the same until being replaced by completely iron rails in the 1850s.

British North America's first locomotive arrived at Molson's wharf in Montreal in June 1836. It was named Dorchester and had been constructed by Robert Stephenson, son of George Stephenson who was the manufacturer of The Rocket. A wood-burning 0-4-0 design, it was the 127th locomotive built by Stephenson and was nicknamed "Kitten" by those who observed its uneven "skittish" ride – a result of the short wheelbase. Trial runs took place at night to avoid frightening the public; maximum speed was approximately 30 mph (48 km/h).

The C&SL opened to great fanfare on July 21, 1836, with several distinguished guests in attendance besides Molson, including Lord Gosford, the Lieutenant-Governor of Lower Canada, as well as Louis-Joseph Papineau, the rebel politician. Over 300 guests crowded the passenger cars in Laprairie station for the first run. The Dorchester was unable to handle such a load, therefore the two first-class coaches carrying 32 of the distinguished guests were uncoupled and hauled by the locomotive while the remaining cars were hauled by teams of horses. Two hours later, everyone was at the station in St. John where the ceremonies continued.

in 1999, the Dorchester was inducted into the North America Railway Hall of Fame. Due to its unique status as the first locomotive used in Canada, it was recognized for its contribution to the railway industry as "Rolling Stock" in the "National" category.