Book excerpt: This book chronicles the development of metal truss and related bridges in Maine, New Hampshire and Vermont from the 1860s to 1940: the various types and their inventors, historical changes in the highway and railroad networks that caused these bridges to be built, the rise of state bridge-building agencies, developments in the field of civil engineering, and preservation trends. While many notable metal bridges of the past are discussed in the context of these topics, the book's main focus is a detailed account of the remaining historic bridges.