Louis Friedman

Not living with his wife and children in either the 1870 or 1880 Federal census. One tree has him dying between 1870 and 1894.... hmmm....

Likely death record: https://www.familysearch.org/ark:/61903/1:1:2WJ9-LPP showing Louis died on 8 November 1869 in Manhattan
Letters of Administration were granted to Cecilia E. Friedman for Louis Friedman on 10 November 1869 per https://www.familysearch.org/ark:/61903/3:1:3QSQ-G995-L9FD-9

CLUE: His 1866 marriage announcement says that he is from Cincinnati.

J. Robert Oppenheimer: And the American Century

Ella Friedman, beautiful, slender, and of distinguished culture and bearing, was the daughter of the German-Jewish immigrant Louis Friedman and his American-born wife, the former Cecilia Eger, the non-Jewish child of a German father and an Austrian mother. It was from his mother and grandmother that Robert Oppenheimer inherited his brilliant blue eyes. Ella had studied art in Baltimore and Paris and offered private painting lessons at home and in art classes at a local college.21 After Louis Friedman died in the early 1890s, Ella remained with her widowed mother in the family apartment at 148 West Ninety-fourth Street. Probably she met the future president of Rothfeld, Stern and Co. through the Rothfelds, who may have known her father through the textile trade or through mutual friends in the Society for Ethical Culture. Although the Rothfelds and Oppenheimers were prominent members of the society, the Friedmans were not.