Ambrose was a really good historian and writer.
One key character was Theodore Judah, who conceived and surveyed a track across the Sierras. My company grew for years on Judah Street, and I was skiing on Mt Judah yesterday. Not many engineers get that sort of fame.
"In England and Europe, after George Stephenson launched the first locomotive in 1829, little of significance in design change took place for the next thirty years. In America nearly everything did, because of the contempt for authority among American engineers, who invented new ways to deal with old problems regardless of precedent."
Neat: Design is rooted in contempt for authority.