Not for long was the Industrial Revolution confined to Britain. It soon spread to continental Western Europe, and by the end of the nineteenth century, it was well under way in the United States, Russia, and Japan. The globalization of industrialization had begun. Everywhere it took hold, industrialization bore a range of broadly similar outcomes. New technologies and sources of energy generated vast increases in production and spawned an unprecedented urbanization as well. Class structures changed as aristocrats, artisans, and peasants declined as classes, while the middle classes and a factory working class grew in numbers and social prominence. Middle-class women generally withdrew from paid labor altogether, and their working-class counterparts sought to do so after marriage. Working women usually received lower wages than their male counterparts, had difficulty joining unions, and were accused of taking jobs from men. Working-class frustration and anger gave rise to trade unions and socialist movements, injecting a new element of social conflict into industrial societies.

Nevertheless, different histories, cultures, and societies ensured that the Industrial Revolution unfolded variously in the diverse countries in which it became established. Differences in the pace and timing of industrialization, the size and shape of major industries, the role of the state, the political expression of social conflict, and many other factors have made this process rich in comparative possibilities. French industrialization, for example, occurred more slowly and perhaps less disruptively than did that of Britain. Germany focused initially on heavy industry—iron, steel, and coal—rather than on the textile industry with which Britain had begun. Moreover, German industrialization was far more highly concentrated in huge companies called cartels, and it generated a rather more militant and Marxist-oriented labor movement than in Britain.

Nowhere were the variations in the industrializing process more apparent than in those two vast countries that lay on the periphery of Europe. To the west across the Atlantic Ocean was the United States, a young, vigorous, democratic, expanding country, populated largely by people of European descent, along with a substantial number of slaves of African origin. To the east was Russia, with its Eastern Orthodox Christianity, an autocratic tsar, a huge population of serfs, and an empire stretching across all of northern Asia. In the 1830s, the French observer Alexis de Tocqueville famously commented on these two emerging giants in his book Democracy in America:

By the early twentieth century, his prediction seemed to be coming true. Industrialization had turned the United States into a major global power and in Russia had spawned an enormous revolutionary upheaval that made that country the first outpost of global communism.