During the days of the American Industrial evolution, names such as Carnegie, Morgan, and Rockefeller regularly appeared in leading newspapers around the country. These were family dynasties who literally cornered the market on essential industries, including railroads, iron ore, and coal. If the industrialist in question used his political and corporate influence for his own selfish ends, he could be described as a robber baron. If the same powerful industrialist used his wealth to improve the lives of others or to bolster the economy in a positive way, he could just as easily be designated a captain of industry.
A captain of industry, at least as understood during the late 19th century, was a powerful force to be reckoned with in his chosen field of interest. In an era where business monopolies were rarely if ever regulated by the government, a man of means could use any number of business practices to gain substantial control over a key resource or manufacturing process. These practices were not always legal or ethical, but the results were usually favorable for the magnate and his family. Such industrialists and robber barons were often one and the same, depending on their interest or disinterest in the welfare of others.
When many people think of a legitimate captain of industry, the name Andrew Carnegie often appears. Carnegie held a virtual monopoly on the steel industry, but used his considerable wealth to fund hospitals, museums, schools, and other public institutions around the country. Carnegie's generosity and philanthropy established his good reputation, even if his own business practices and monopolistic tendencies kept him under government scrutiny.
As the federal government and private business regulators began to systematically dissolve business monopolies, the era of the robber baron eventually came to an end. Leading industrialists continued to practice some form of philanthropy, mostly in the form of generous endowments or scholarships, but there were far fewer individuals who could still be described as captains of industry.
Today, there are a handful of successful industrialists and entrepreneurs who could honestly be described with this term. Many people consider the founder of Microsoft, Bill Gates, to be such a person, since he and his wife continue to fund public works through their Gates Foundation. Others consider leading businessmen such as Donald Trump or T. Boone Pickens to be the modern equivalents, as each has made substantial contributions to environmental or social programs. The concept primarily has to do with the perception of the selflessness by the industrialist in question.