The New York Nobody Knows, by William B. Helmreich

Helmreich, a sociologist at the City University of New York, had an excellent idea: he walked nearly every block in the five boroughs of New York City—6,000 miles over a period of four years. He tried to remain as inconspicuous as possible, while also engaging people along the way. What he learned was that New Yorkers from every walk of life are friendly and that few ever refused to engage him in conversation. Most even agreed to have their conversation taped. Helmreich doesn’t use as much of his on-the-ground research as he might have. The material is organized topically, rather than by streets or neighborhoods, and he draws on many other sources about the city. The book is an excellent introduction to one of the most ethnically diverse and vibrant cities in the world, and a model of urban sociology.