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- Imperial Rolling Stock Company
- Indiana Railway
- Industrial Land Company
- Intercolonial and Prince Edward Island Railways Employees, Provident Fund
- Intercolonial Express Company of Canada, (Limited)
- Intercolonial Railway
- Intercolonial Railway Windsor Branch
- International Bridge Company
- International Railway of New Brunswick
- Inverness Coal, Iron and Railway
- Inverness Coal, Field and Railway
- Inverness Railway and Coal Company
- Inverness Railway
- Inverness - Richmond Collieries and Railway of Canada
- Inverness and Richmond Railway
- Irondale, Bancroft and Ottawa Railway
Read more about this topic: List Of Canadian National Railways Companies