The document provides an overview of major economic, political, and social transformations in the United States during the Gilded Age from 1865 to 1920. Key developments include a rapid increase in population, manufacturing, and GDP, leading the country to become a global industrial power. New large-scale corporations dominated industries like steel and railroads. Wealthy industrialists known as "robber barons" like Jay Gould and Andrew Carnegie amassed huge fortunes but were widely disliked. Labor unrest grew as unions like the Knights of Labor organized workers seeking better conditions. Corruption was also widespread as business interests increasingly influenced government.