What various practices of industrialists/financiers led to their being labeled robber barons

ome nineteenth-century industrialists who were called "captains of industry" overlap with those called "robber barons," however. These include people such as J. P. Morgan, Andrew Carnegie, Andrew W. Mellon, and John D. Rockefeller. The positive term was coined by Thomas Carlyle in his 1843 book, Past and Present.