Engineering landmarks on the way to overcoming natural obstacles, presented with blueprint precision and historical acumen. The list of feats parallels the expansion and consolidation of American transport: each is seen as the consequence of improvements in material and techniques, of experience buttressed by theoretical investigation. The canals come, the railroads supersede them, the track preceding the train; bridges must now bear sudden, concentrated loads in motion, tunnels must take the trains through the mountains; the Mississippi is spanned at St. Louis by James Leads (with an assist from Andrew Carnegie), the suspension bridge is exploited by Charles Ellet and John Recbling; ""a great time for doing"" brings the Panama Canal, the Holland Tunnel, the George Washington Bridge (and related developments in Europe): productive rivalry between David Steinman and Othmar Amman further extends the suspension span. Most of this information can be found in other sources; here it is part of a concentrated, interrelated, investigation that's impressively documented (see especially the photos of structures abuilding, e.g. the arches of the St. Louis Bridge reaching toward each other, the cable anchorage of the Verrazano Bridge before it was covered). The appendix is a separate, secondary source containing a chronology, a diagrammatic explanation of ""the essentials of bridge building,"" and such electeras as accounts of opening celebrations. Highly instructive for interested readers of any age.