Wealthy doctor who built an industrial empire including Occidental Petroleum. Much of his early wealth came from a willingness to deal with the Soviet Union in the 1920s, when others refused to do so. In his initial business with the Soviets, he founded a pencil company that used Soviet wood. Later in life, he claimed to be the only man to have met both Vladimir Lenin and Ronald Reagan.
As the Soviets were often poor in hard currency, Hammer sometimes accepted artwork in payment and thereby built an extraordinary personal collection of art (technically, the art belonged to his company, but he treated it as a personal collection to the point of building a museum with Occidental Petroleum's money, filling it with art that Occidental Petroleum owned, and calling it the "Armand Hammer Center").
Because of his williness to associate himself with the Soviets, and because his father was a representative at the Second International, Hammer has often been accused by reactionaries of being a communist spy. These claims were heard frequently during the 2000 election campaign in the United States, as Hammer had been a supporter of Al Gore and his father, and attacking Hammer was a way to smear Gore as well.
In the later years of his life, Hammer actively campaigned for a Nobel Peace Prize, though he never won one.
He gave a great deal of money to charities, and founded the Armand Hammer United World College of the American West.