Now, finally got started on McPherson's Battle Cry of Freedom. Even the first chapter, general US history, has something very important snuck in it.
One of the reasosn for massive US growth given, is that skilled labour was relatively short - i.e. that the costs of labour drove the demands for capital's innovation.
Obviously, the population was growing, and much of this shortage would be due to the fact that a good many people preferred to work their own land than suffer the ignomany of being a wage-slave (another point McPherson covers).
Even still, it is a good counter-intuitive example of the way in which it has been the working class that made capitalism - contrary to some of the passive models of some anarchist and leftist flavours which see the active agent of history as the ruling class.
Now, it also illustrates some of the problems faced by developing countries - they have plentiful surplus population - along with infrastructure built up on labour intensive colonial industries due to cheaply available labour. The only developmental answer to that situation so far has been dictatorship - a route Western countries could face going downas their relatively surplus poulations increase (although at the minute government policy is directed at aiding tech development/advancement, sometimes through disguised military spending - even then, all the western powers are at it, and the cultural capital of technical expertise is rapidly being globalised as well).
Perhaps in this historical lesson there is a case for a revision of capitalist decadence theory - without a vibrant and advancing working class capitalism is nothing.