Article: Amtrak's Northeast Corridor and Chicago lines originate at South Station, which serves as a major intermodal transportation hub, and stop at Back Bay. Fast Northeast Corridor trains, which serve New York City, Washington, D.C., and points in between, also stop at Route 128 Station in the southwestern suburbs of Boston. Meanwhile, Amtrak's Downeaster service to Maine originates at North Station, despite the current lack of a dedicated passenger rail link between the two railhubs, other than the "T" subway lines.

Question: Where do Amtrack's Northeast corridor and Chicago lines start?
South Station