Industrialization is the social and economic organization characterized by large industries, machine production, and the concentration of workers in towns and cities. In the northern United States, industry emerged in the early 19th century, especially in the New England states where textile mills proliferated. In the decades following the Civil War, the United States emerged as an industrial giant. Old industries expanded and many new ones, including petroleum refining, steel manufacturing, and electrical power, emerged. Railroads expanded significantly, bringing even remote parts of the country into a national market economy.