John Pierpont Morgan was a wealthy industrialist who emerged from the 19th century as one of the most powerful financiers of the 20th century -- he formed U.S. Steel, America's first billion-dollar corporation, in 1901. He got his start in business in the late 1850s, with the New York branch of a banking firm run out of London by his father, Junius Morgan. With Anthony Drexel, John Pierpont Morgan formed Drexel, Morgan & Co. in New York in 1871 (it became J.P. Morgan & Co. in 1895). During the 1890s Morgan was the big money behind the expanding U.S. rail system -- what Andrew Carnegie was to steel and John D. Rockefeller was to oil. Morgan bought out Carnegie's steel companies, and formed the consortium U.S. Steel, a corporation comprised of nearly three dozen companies, with capitalization exceeding a billion dollars (a world first). In the early years of the 20th century, J.P. Morgan was emblematic of the era's "robber barons." He consolidated important parts of the U.S. economy and became crazy rich, with mixed results. Morgan's rivalry with railroad baron E.H. Harriman caused the first stock market crash, ruining thousands of investors in 1901. But it's been generally agreed he saved the day during the Panic of 1907, and acted as an unofficial central bank for the U.S. economy in the first part of the 20th century. In his later years he was known as a great art collector and philanthropist.
J.P. Morgan was a secret (and unsatisfied) investor in the first American projects of electrical genius Nikola Tesla.