Yesterday the New York Department of State announced $23.3M in grants from the environmental protection fund, for 88 waterfront revitalization projects in NYS. No projects were included for Rensselaer in this round of funding, but the City of Troy received money to support their planned Hudson River promenade and park at the former Rensselaer Iron Works site at the end of Madison St.
The New York Times archives has this article detailing a shut-down of the Albany and Rensselaer Iron Works, almost 125 years ago. This history of labor and industry from SUNY Albany describes the lives of the iron workers in Troy. These Wikipedia articles on Erastus Corning and John F. Winslow include some history of the Iron Works as well.
You can walk along Madison Street circa late summer 2007 using Google Maps Street View, but there isn't an exact address to link you there. This image (c2008 Google) is from Google Satellite view.