A term used to refer to a rich/powerful banker or businessman during the Gilded Age.
"Robber baron" is a term used for a powerful 19th century United States businessman or banker. It was popularized by U.S. political and economic commentator Matthew Josephson during the Great Depression in a book in 1934.
Rich bankers or businessman such as Carnegie (Steel mill owner) or Rockerfeller (Oil tycoon) were often villianized by the public and commonly refered to in a negative way. This word is an example of this and how the public viewed them as the sum of all evils. Consider it the derogatory equivalent of "Captain of Industry."