This document discusses several influential businessmen from the late 19th century known as Robber Barons or Captains of Industry, including Andrew Carnegie, Cornelius Vanderbilt, J.P. Morgan, John D. Rockefeller, and James Buchanan Duke. It also examines the technological advances of the time period, such as railroads, oil drilling, steel production, electricity, and inventions, and how these impacted industrialization and economic growth in the United States.