Final answer:
The term 'robber baron' was used to negatively describe influential American industrialists of the nineteenth century who were seen as exploiting workers and the legal system to accumulate vast wealth.
Step-by-step explanation:
The term robber baron was used to criticize powerful nineteenth-century American businessmen who were perceived as using unethical methods to amass their wealth. The exploitation of labor, manipulation of prices, and bending of laws were commonly attributed to these individuals. Notable examples include Jay Gould, who manipulated the railroad industry for personal gain, and John D. Rockefeller, whose ruthless business tactics in the oil industry led many to view him as a robber baron. Despite their negative reputation, these industrialists also contributed to the development and transformation of the American economy, sometimes with significant philanthropic efforts, blurring the line between being a robber baron and a captain of industry.