Question: The first railway in British North America, the Champlain and St. Lawrence Railroad, was built when to track gauge, However the promoters of St. Lawrence and Atlantic Railroad, (intended to connect Montreal to the ice-free port at Portland, Maine) decided to use , setting a precedent for the colony for several decades, The St. Lawrence and Atlantic Railroad (reporting mark SLR) , known as St-Laurent et Atlantique Quebec (reporting mark SLQ) in Canada, is a short line railway operating between Portland, Maine, on the Atlantic Ocean and Montreal, Quebec, on the St. Lawrence River?

Context paragraphs:
Adirondack and St. Lawrence Railroad: The Adirondack and St. Lawrence Railroad operated between DeKalb Junction and Hermon in St. Lawrence County, New York over a four-mile standard gauge railroad.  The Adirondack&St. Lawrence was founded by the St. Lawrence Pyrites Company on April 19, 1906, and shortly thereafter the line was opened.  Not only due to a parallel railroad of the Clifton Iron Company, traffic was low and in 1925 the line was abandoned and torn up.  Still today the right-of-way can be observed near DeKalb Junction.  In Hermon, the roadbed is now used by Water Street.

Track gauge in Canada: The first railway in British North America, the Champlain and St. Lawrence Railroad, was built in the mid-1830s to track gauge.  This was followed by the Albion Colliery tramway in and the Montreal and Lachine Railroad in .  However the promoters of St. Lawrence and Atlantic Railroad, (intended to connect Montreal to the ice-free port at Portland, Maine) decided to use , setting a precedent for the colony for several decades.  The first section from Longueuil to St. Hyacinthe opened in 1847 and at the end of that year there were 30 mi of broad gauge and 22 mi of standard gauge in Canada.

Portland Company Marine Complex: The Portland Company Marine Complex is an 9 acre industrial site in Portland, Maine's East End neighborhood.  The Portland Company was established in 1846 and built railroad equipment for the adjacent Portland terminus of the Atlantic and St. Lawrence Railroad connection between Portland and Montreal.  It ceased production in 1978.  In August 2013, the property was sold to a group of developers.  At the time of its sale, the property had a tax-assessed value of $1.9 million.  Since 1993, the building has been home to the Maine Narrow Gauge Railroad Museum as well as host to the annual events Maine Boat Show and Maine Flower Show.

Lordship of Sainte-Anne-de-la-Pérade: The Lordship of Sainte-Anne-de-la-Pérade was located on the north shore of St. Lawrence river, between Trois-Rivières and Quebec City in the province of Quebec, Canada.  The southern front of the manor was on the edge of St. Lawrence river.  The depth of the lordship was heading north, parallel to the Lordship of Batiscan (on West side).  The northern boundary of the Lordship of Sainte-Anne-de-la-Perade stopped at the north-western boundary of St. Joseph row, in Sainte-Thècle.  In comparison, the lordship of Batiscan spanned 20 "lieues", beyond the Saint-Maurice River.  The western boundary of the manor cut the Batiscan river at the rapids of Manitou, between Saint-Adelphe and Saint-Stanislas.  The estates of the north shore of St. Lawrence river fell within the stately administrative division of Trois-Rivières.

Grand Trunk Station (Oxford, Maine): The Grand Trunk Station was a historic railroad station in Oxford, Maine.  The station was built in 1883 by the Grand Trunk Railroad linking Oxford with Montreal and Portland, Maine.  The village grew especially after the arrival of the St. Lawrence & Atlantic Railroad toward the end of 1840.  The railroad opened the village to several business ventures between Portland and Montreal.  The railroad passes through the midst of the town, in the same general line with the river, and has a station (Oxford Depot) a short distance south of the centre.

Champlain Valley: The Champlain Valley is a region of the United States around Lake Champlain in Vermont and New York extending north slightly into Quebec, Canada.  It is part of the St. Lawrence River drainage basin, drained northward by the Richelieu River into the St. Lawrence at Sorel-Tracy, Quebec (northeast of Montreal).  The Richelieu valley is not generally referred to as part of the Champlain Valley.

Portland Company: The Portland Company was established 10 November 1846 by John A. Poor and Norris Locomotive Works engineer Septimus Norris as a locomotive foundry to build railroad equipment for the adjacent Portland terminus of the Atlantic and St. Lawrence Railroad connection between Portland, Maine and Montreal.  The shops opened for business in October, 1847.  Its first locomotive, the Augusta, emerged from the shops in July 1848 for delivery to the Portland, Saco & Portsmouth (later part of the Boston and Maine Railroad).  Over the next several decades, the Company produced in its Fore Street facilities over 600 steam locomotives as well as 160 merchant and naval vessels, railcars, construction equipment, Knox automobiles, and the like.  Portland Company built the engines of the civil war side-wheel gunboats "Agawam" and "Pontoosuc" .  Taking into account its other products, the Company could lay claim to being one of the leading medium-to-heavy steel manufacturers in New England.  The company ceased production in 1978.

Quebec Central Railway: The Quebec Central Railway (reporting mark QCR) was a railway in the Canadian province of Quebec, that served the area of Quebec called the Eastern Townships, south of the St. Lawrence River.  Its headquarters was in Sherbrooke.  It was originally incorporated in 1869 as the Sherbrooke, Eastern Townships and Kennebec Railway, and changed its name to the Quebec Central Railway in 1875.  In 1894, it built a line southward to Mégantic to connect to CP's east-west line, the International Railway of Maine.  It would eventually own around 300 mi of track.  In 1912, the Canadian Pacific Railway leased the Quebec Central for 99 years but continued to operate as Quebec Central Railway, including passenger service to American cities.  The Quebec Central in turn leased the Massawippi Valley Railway, a short line from Lennoxville to Newport, in 1926; this allowed passenger service from Québec City via Sherbrooke to the United States of America.

Oregon Short Line Railroad: The Oregon Short Line Railroad (reporting mark OSL) was a railroad in the U.S. states of Wyoming, Idaho, Utah, Montana and Oregon.  The line was organized as the Oregon Short Line Railway in 1881 as a subsidiary of the Union Pacific Railway.  The Union Pacific intended the line to be the shortest route ("the short line") from Wyoming to Oregon.  In 1889 the line merged with the Utah & Northern Railway and a handful of smaller railroads to become the Oregon Short Line and Utah Northern Railway.  Following the bankruptcy of Union Pacific, the line was taken into receivership and reorganized as the Oregon Short Line Railroad.

St. Lawrence and Atlantic Railroad: The St. Lawrence and Atlantic Railroad (reporting mark SLR) , known as St-Laurent et Atlantique Quebec (reporting mark SLQ) in Canada, is a short line railway operating between Portland, Maine, on the Atlantic Ocean and Montreal, Quebec, on the St. Lawrence River.  It crosses the Canada–US border at Norton, Vermont, and is owned by short line operator Genesee and Wyoming.

Supporting paragraphs: Track gauge in Canada St. Lawrence and Atlantic Railroad
Answer: mid-1830s