Robber baron is a term first applied as social criticism by 19th century muckrakers and others to certain wealthy, powerful, and unethical 19th-century American businessmen. The term appeared in that use as early as the August 1870 issue of The Atlantic Monthly magazine. By the late 19th century, the term was typically applied to businessmen who used exploitative practices to amass their wealth. Those practices included unfettered consumption and destruction of natural resources, influencing high levels of government, wage slavery, squashing competition by acquiring their competitors to create monopolies and/or trusts that control the market, and schemes to sell stock at inflated prices to unsuspecting investors. The term combines the sense of criminal ("robber") and illegitimate aristocracy (“baron”) in a republic.

Jason Gould was an American railroad magnate and financial speculator who founded the Gould business dynasty. He is generally identified as one of the robber barons of the Gilded Age. His sharp and often unscrupulous business practices made him one of the wealthiest men of the late nineteenth century. Gould was an unpopular figure during his life and remains controversial.