In the last decades of the nineteenth century, the United States was at a crossroads: a sparsely populated agricultural country, only a few hundred years away from the wilderness discovered by the colonists, was about to enter a period of unprecedented economic growth to become the world's greatest industrial nation. A large part in this economic transformation was played by inventors, a group of men who devised the new technology which was the key to rapid industrialization. Their achievements were acknowledged worldwide as the “Yankee ingenuity” that transformed the United States into an industrial giant.

Of all the inventors of the nineteenth century, Thomas Edison is the best known. Statistically he holds the most U.S. patents (a record which will probably never be beaten), and mythologically he is the world's greatest inventor – the “Wizard of Menlo Park” whose magic helped create the modern industrial society in which we live. Edison became a legend in his own time; unlike most of his fellow inventors, he died rich and famous.

The invention which gained Edison his fame was the phonograph. Although nowadays we think of this machine as a mechanical entertainer, it was in fact part of a communications revolution, a revolution which brought so many dramatic changes in American life that it far exceeds any of the so-called communications or computer revolutions of the twentieth century. By 1850 inventors had developed a system of communications in which an electric current could be used between two places to replace the letter delivered by hand or by horseback. Messages now moved at the unimaginable speed of electricity. The rapid communications afforded by the telegraph became one of the foundations of American industrial growth. By the 1860s it had spawned a great international business and a host of research laboratories: the telegraph was the high-tech field of the 1860s and 1870s.

Edison was part of this dynamic new field of telecommunications. He was one of many ambitious young men who saw the telegraph as the most profitable field for new inventions.