Robert was born in New York City on April 22, 1904.
His father was Julius Seligmann Oppenheimer, a wealthy textile importer who came to the United States from Germany as a teenager in 1888. He had no money, no education, and no knowledge of English. Julius was hired by the textile company and after ten years became its president.
Robert's mother, Ellie Friedman, whose family also came from Germany but had settled in New York in the 1840s, was a painter.
