The industrialization of the United States began in the early 1800s, fueled by free enterprise and new technologies. Factories sprang up and large cities grew as thousands moved from farms to urban areas for work. Textile mills, established by Samuel Slater and Francis Lowell, drove the growth of the cotton industry. Infrastructure projects like the National Road, Erie Canal, and railroads connected regions and markets, facilitating trade and western expansion. The economies of the North and South diverged, with the North industrializing and the South specializing in cotton and slavery. Inventions like the cotton gin, reaper, telegraph, and interchangeable parts advanced industry and agriculture.