In Minnesota, Angus had worked closely with James J. Hill, constructing and improving the line. But by 1880, he spent most of his time with Mount Stephen as they made numerous trips to Ottawa, New York, and London to negotiate the land grants, subsidies, and building of the Canadian Pacific Railway. With Angus providing the analysis and Mount Stephen the acumen, they proved to be a formidable pair. Angus was general manager of the CPR until the appointment of Sir William Cornelius Van Horne in 1882, when Angus became vice-president. In that position, Angus was entrusted with the creation of the eastern network, notably the extension of the Ontario and Quebec Railway and the purchase of the western section of the 'Quebec, Montreal, Ottawa and Occidental Railway' in 1882.