Final answer:
Industrial capitalist leaders Andrew Carnegie and John D. Rockefeller are known for their business strategies of vertical and horizontal integration, which led them to dominate their respective industries. They were admired for their successes but also criticized as 'robber barons' for their methods of competition and negative impact on others.
Step-by-step explanation:
The industrial capitalist leaders of the late 19th century, Andrew Carnegie and John D. Rockefeller, employed various strategies to build their businesses. Carnegie, who rose from modest means and became the dominant force in the American steel industry, practiced vertical integration by purchasing all stages of production, from raw materials to transportation, allowing him to cut costs and ensure quality control. Rockefeller, who led Standard Oil, utilized not only vertical integration but also horizontal integration, buying out competitors to monopolize the oil industry, often through ruthless tactics that drove others out of business.
These leaders were admired for their business prowess, with Carnegie leading the expansion of the American steel industry and Rockefeller greatly reducing kerosene prices. However, they were also perceived as 'robber barons' due to their aggressive business practices that decimated competition and raised questions regarding their ethical conduct and the impact on workers and consumers.