Final answer:
Andrew Carnegie controlled most of the steel industry in the late-19th century.
Step-by-step explanation:
Andrew Carnegie controlled most of the steel industry in the late-19th century. He was a Scottish-American industrialist and philanthropist who founded the Carnegie Steel Company, which eventually became the largest and most profitable steel company in the world. Carnegie's business practices and innovations revolutionized the steel industry.
Learn more about Andrew Carnegie and the steel industry