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.

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!

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.

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.

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.

It wasn't openly talked about very much, in the sense that people said they wanted to beat GB at this or that, but there would however be sidelong comparisons frequently in press commentary. And it was also pretty quickly obvious that no other countries were developing the kind of technological depth of industry as were the US and the UK.

The kind of precision manufacturing epitomized in the armories, while it was important, was only a small share of the economy until quite late in the century. Large-scale natural resource development and processing was the name of the game.