Librarian of the Smithsonian Institution; founder of the American Jewish Historical Society. He was born at Van Buren, Arkansas, Sept. 13, 1863, and was educated at the Philadelphia High School, University of Pennsylvania (B.A., 1883; M.A., 1886), and Johns Hopkins University (Ph.D., 1887). He was fellow in Semitic languages at Johns Hopkins University, 1885-87, was appointed instructor in Semitic languages, 1887, and associate, 1892. Adler became assistant curator in the department of Oriental antiquities in the United States National Museum, in Washington, in 1887, and custodian of the section of historic religious ceremonials in 1889.
He went to the Orient for fifteen months as special commissioner for the World's Columbian Exhibition at Chicago, at which the Oriental exhibits were obtained mainly through his efforts; he also participated in the organization of the United States Government exhibits at the expositions at Cincinnati, 1888, at Chicago, 1893, and at Atlanta, 1895; of the last-named he, together with Dr. I. M. Casanowicz, published an illustrated catalogue in the "Report of the United States National Museum for 1896" (pp. 943-1023, with 46 plates). Adler may justly be regarded as the originator of the American Jewish Historical Society, which was the outcome of an appeal issued by him early in 1892. After acting as its secretary from that date he became its president in 1898. Of the many learned societies of which he is member he has acted as vice-president of the Anthropological Society of Washington, as member of council of the Philosophical Society of Washington, and as trustee of the American Jewish Publication Society and of Gratz College. In 1899 he was elected a member of the American Philosophical Society. He has played an important part in the organization of the international catalogue of scientific literature, and represented the United States at the conference on this subject held in London in 1898. Besides the catalogue of Biblical antiquities at the Atlanta Exposition and other papers in the reports and proceedings of the United States National Museum and in the journals of the learned societies of which he is a member, Adler has published, with Allan Ramsay, "Told in the Coffee House" (New York, 1898), a series of folk-tales collected in Constantinople; and has edited the "American Jewish Year Book" since 1899.
- H. S. Morais, The Jews of Philadelphia Prior to 1800, Philadelphia, 1883;
- Appleton's Cyclopedia;
- Who's Who in America, s.v.;
- Fifty Years' Work of the Hebrew Educational Society of Philadelphia, p. 62.