 His son-in-law, Charles-Ignace Gill, a member of the Legislative Assembly of Quebec, helped provide Senécal with the required political connections for railway construction and also looked after some of Senécal's other business interests while he was otherwise occupied.In 1880, he was named superintendent for the Quebec, Montreal, Ottawa and Occidental Railway; sections of this railway were later sold to the Canadian Pacific Railway and the Grand Trunk Railway.Senécal was also treasurer for the Parti conservateur du Québec during this period which many saw as a conflict of interest because of the heavy government involvement in railways at the time.