[Prologue] This is the story of improvements and better ways of life which have come into being over the course of the last one hundred years. Inventiveness and ingenuity created the improvements - but the force which brought them into widespread use has been American salesmanship. Improved commodities and services never have been quickly or universally accepted. They have to be sold. So, it is to these salesmen that this picture is dedicated - to the men and women who, in the performance of their daily tasks, are building a better world in which to live.