The Second Industrial Revolution was a period of groundbreaking advancements in manufacturing, technology, and industrial production methods, particularly in the United States, from around 1870 to 1914. Developments such as steel, electricity, increased mass production, and the building of a nationwide railroad network enabled the growth of sprawling cities. This historic boost in factory output, coupled with the invention of technological marvels such as the telegraph, the telephone, the automobile, and the radio would forever change how Americans lived and worked.