He was an expert mechanic and after being employed as a skilled workman by several firms he
determined to engage in business on his own account and in 1853 established the James Shearer Company, a factory for the manufacture of house and steamboat woodwork finishings and interior trim of all descriptions. Under Mr. Shearer's careful direction the business for the manufacture of lumber, doors, sashes and blinds was carried on along extensive lines, and the new business grew to such large proportions that led to the formation of a separate company, in the year 1895, of the Shearer & Brown Company, for the manufacture of dimension timber, etc. In the year 1903 these two companies amalgamated under the name of Shearer, Brown & Wills, Limited, with Mr. Shearer as president and took over the mill properties in the vicinity of the St. Gabriel Locks of the Lachine Canal. These mills are ranked among Montreal's leading industries. Mr. Shearer retired from active business in 1903 and was succeeded in the presidency of the company by his eldest son, James T. Shearer, who died September 7, 1908.

The greater part of Mr. Shearer's shipping being by water he was naturally interested in that means of transportation and was a staunch advocate of harbor improvements. He had on many occasions seen the low-lying wharves and piers lining the St. Lawrence River completely inundated during the high tides of early spring, and he knew the entire system was wrong and totally inadequate for the shipping at that period. His thoughts were not entirely for his own day, but with the rare business discernment he possessed, he could see the city's wonderful growth as a great maritime port, and he was anxious that adequate provision be made for the increase in shipping that he knew was bound to come. With this end in view he worked out a plan of  harbor improvement and labored zealously to have his ideas adopted by the Harbour Commission. His plans included the dredging of the harbor to a uniform depth, the widening of the channel at certain points, the raising of the old wharves, which were at that time at a low level, and the construction of additional piers at a high level. Mr. Shearer's plans were considered premature at the time and he labored in vain to have them adopted. After he had relinquished his efforts, however, shipping interests were aroused to the necessity of improved shipping facilities, and while Mr. Shearer received no credit for his foresight, he lived long enough to see the improvements he had so strongly advocated underway, along the very lines that he planed [sic] and labored for a quarter of a century earlier.

Mr. Shearer married in June, 1848, Miss Eliza Graham, of Montreal, [daughter of Francis Graham and Eleanor O'Rourke] and died September 13, 1906.

During his long and honorable business career, Mr. Shearer was one of the strongest figures in the city's commercial life. He was always interested in every movement that would advance the welfare of the city of his adoption and any work that paid tribute to Montreal's makers would be
incomplete unless it included his name among those who have be strict integrity and business acumen made Montreal commercially great.

On January 7th, 1912, the name of the firm was again changed to its original name of the James Shearer Company, Limited, with Mr. James Gilman Shearer, grandson of the founder of the company, as president.

JAMES TRAILL SHEARER, contractor, Montreal, is a specimen of what well-directed energy and perseverance can accomplish. Born at Rosegill, parish of Dunnet, not many miles from far-famed John O'Groat's, Caithnessshire, Scotland, on the 31st of July, 1822, he received his education in the parish school of Dunnet, and at Castletown, in the same county. 

Leaving school before he had scarcely entered his teens, he was obliged like many a lad in the far north of Scotland, to begin work early, and was accordingly apprenticed to a carpenter and millwright in the village of Castletown, and with him he faithfully served the alloted term. To perfect himself in his trade, he removed to Wick, and worked for about a year under D. Miller, a builder, who was erecting a church in Putneytown. 

When he reached his twenty-first year he resolved to try his fortune in Canada, and taking passage in a sailing vessel, on 30th May, 1843, reached Montreal, where he has since resided. Shortly after his arrival he entered the employ of Edward Maxwell, an extensive carpenter and builder, as a general house-joiner and stair-builder, branches of the business at which be was very proficient. After terminating a three years engagement with Mr. Maxwell, he went to Quebec city to take charge of the joiner and carpenter work on a new bomb-proof hospital then being built by the British Government on Cape Diamond. 

Finishing the job to the entire satisfaction of the British officers in charge, he returned to Montreal, and began the study of steamboat architecture, especially cabin work, and soon became an adept at the business. Work flowed in upon him, and he found many customers, among others the late John Molson and David Torrance, for whom he fitted up many steamboats for the St. Lawrence and Ottawa rivers, and he still carries on very extensively this branch of business, along with the manufacture of other kinds of wood-work for house-building purposes. 

Mr. Shearer is the inventor of what is known as the hollow roof, for houses and large public buildings, which is considered the best suited for the climate of Montreal. This roof is of a concave design, and carries the water down the inside of the building, instead of the outside, thereby avoiding the freezing up of pipes. It was used on the Windsor Hotel, Montreal, and has since been adopted generally throughout America. 

He has also been the chief promoter of what is known as the "Shearer scheme," tile object of which is to improve the harbor of Montreal and prevent the flooding of the city, but owing to the strong opposition urged against it by the Grand Trunk authorities, he has had to abandon it for the present. However, it will have to be considered at no distant day. If once adopted it will greatly improve the harbor of Montreal, and prove a source of wealth to the inhabitants. The plans are now in the possession of the Dominion government, and although he has twice applied for an act of incorporation for the "St. Lawrence Bridge and Manufacturing Company," who are prepared to carry it to completion, he has not yet succeeded in getting this company incorporated. 

Mr. Shearer, a few years ago, designed and built for himself a house on Mount Royal, and it is perhaps the best finished house in that city of fine dwellings, all the internal work being of purely Canadian wood. The view from it is most charming, and cannot be surpassed in the Dominion. A visitor can take in at a glance the Chambly hills, Belle Isle, Mount Johnston, the River St. Lawrence for many miles, the Victoria bridge and Lachine rapids, and the full extent of the beautiful city of Montreal.

In politics, Mr. Shearer is a Liberal, and in religion one of those who does his own thinking, and has no objection to others doing the same. He was married in Montreal, on the 23rd of June, 1848, to Eliza Graham, and the fruit of the union has been eight children. Personally, Mr. Shearer is endowed with those qualities which have gained for him the esteem of a large circle of friends.