The Industrial Revolution in the United States took place between 1870 and 1914. During this time, the invention of new technology and machinery began to phase out labor traditionally done by hand—textile work, factory manufacturing, farm labor—and made that labor more efficient with various mechanized systems, often involving new machinery. The technological advances of this period led to the development of the assembly line and spurred the migration of people to cities to seek employment in new and emerging industries. While there were more employment opportunities, working conditions were harsh and unregulated; these conditions would eventually lead to the development of labor unions and government workplace regulations and laws. For the better part of 100 years—from the mid-18th to mid-19th century—American industry had transitioned from a largely agricultural society to an industrial society.

Before the Industrial Revolution, steel was expensive to produce. In the 1850s, Henry Bessemer began developing a process to rapidly convert iron into steel, reducing to minutes what had previously taken a full day. This process revolutionized steel production by decreasing cost and increasing scale and speed, leading to an unprecedented steel industry expansion. At the time of the flood in Johnstown, the American steel industry had begun to expand rapidly, thanks to the Industrial Revolution and the vast expanse of interconnected railroad networks.