His active operations in the field of railway construction included the building of the Credit Valley Railway in 1878-79 and upon its completion he was appointed general manager of the road and also filled the position of consulting engineer of the Ontario and Quebec Railway. In the spring of 1883 as general manager of construction, Mr. Ross began at Swift Current the building of the Canadian Pacific Railway over the Rockies, the Selkirks and the Gold Range, and early in November, 1885, this stretch of six hundred and twenty-three miles ending at Craig Ellachie, was completed more than a year ahead of time, creating a record for fast railway building on this continent and evoking from Sir William Van Horne the statement that such a record meant millions to the Canadian Pacific Railway. It was during the building of the road over the mountains that Mr. Ross might be said to have discovered and subsequently came into close touch with William Mackenzie, Donald Mann (both since knighted), Herbert S. Holt and several others who later on took a front place among the railway magnates and financial leaders of Canada. In 1886 Mr. Ross brought about the settlement of location of the Canadian Pacific east of Montreal and the legislative difficulties attending the entry of the road into the state of Maine. Upon completing his arduous and complex task he took the contract for the construction of the remaining portion of their line not already provided for. The extensions and improvements of the Canadian Pacific created difficult tasks of civil engineering which were ably performed by Mr. Ross who at the same time considered the question of railway construction in South America for which he had options. The railways of the southern continent were to be built in Argentine and Chile and the options in those two republics alone amounted to over twenty million dollars. Mr. Ross was also interested in important contracts in Chicago and elsewhere. He established his home permanently in Montreal in 1888 and from this point supported his active professional interests, contracting and building the Regina and Long Lake Railways some two hundred and fifty miles in length. In 1889 he supervised the construction of the Calgary & Edmonton Railway, three hundred miles in length.