Riis, Jacob A. How the other half lives :studies among the tenements of New York. New York : Charles Scribner's Sons, 1897.

The whole book is here, but you should all read the Introduction, Chapter 1 "Genesis of the Tenement" and Chapter 2 "The Awakening" . Good precedent for your analaysis.

http://pds.lib.harvard.edu/pds/view/4137257?n=1&imagesize=1200&jp2Res=.5

Also see NY Times:

http://cityroom.blogs.nytimes.com/2008/02/28/revisiting-the-other-half-of-jacob-riis/index.html

Riis Photo Slideshow

http://www.nytimes.com/slideshow/2008/02/27/nyregion/20080227_RIIS_SLIDESHOW_index.html