The document summarizes economic and social developments in the Northern United States between 1820-1860. It describes the growth of industry and manufacturing facilitated by new technologies like the cotton gin, sewing machine, and steam power. This led to a boom in Northern cities as many moved to urban areas for work in factories. It also discusses improvements to transportation infrastructure like canals, railroads, and steamships that allowed for increased trade. The rapid industrialization brought both economic opportunity and harsh working conditions, and attracted large numbers of immigrants to the growing industrial centers of the North.