In the 19th century, so-called 'Robber Barons' - men like Cornelius Vanderbilt, Jay Gould, Andrew Carnegie, John D. Rockefeller and J.P. Morgan - seized the great new opportunities thrown up by the United States' Industrial Revolution. Dr Joanna Cohen contributes to the first episode of a series on BBC Radio 4 (link is external)which tells their stories and confronts their legacy