After I finished the Tycoons - on post-Civil War development - I realized how much I didn't know about the first half of the century, even though there had obviously been an enormous amount of development, so I read about and thought about that for a couple of years before I decided I was ready for a book.

My neck is too arthritic to snap around. The big shift in my perspective that happened in the writing process, however, was the paramount importance of the "West" epitomized by Cincinnati.

The evolution was always to greater scale and speed. Other countries did that here and there - GB in textiles, Germany in steel - but we went in that direction almost across the board.

For just a few dollars registration, you got temporary possession of a good piece of land. Live on it for five years, build a house, and farm it, and it was yours. What a brilliant economic stimulus!

The paradigm of the development of natural resource-based industry - meatpacking, lard, timber, iron and coal, grain. Cincinnati's lard processing plants looked a lot like JDR's oil refineries thirty years later.

It's clear that North took some original steps in that direction, but Hall probably had the most complete approach and should get the most credit. But for Hall, unfortunately, the data are all impressionistic - what people said. None of his machinery survived. His patents were all lost in the Patent Office fire.

After I finished the Tycoons - on post-Civil War development - I realized how much I didn't know about the first half of the century, even though there had obviously been an enormous amount of development, so I read about and thought about that for a couple of years before I decided I was ready for a book.