The records of the American Jewish Historical Society, the oldest national ethnic historical organization in the United States, include correspondence of officers and staff as well as inter-office memos, multiple versions of the constitution and by-laws of the society, meeting minutes of administrative branches and committees, membership and financial records, reports, exhibit materials, records relating to the society’s library and archival holdings, press releases and newspaper clippings, and publications and newsletters created by the society. There are also materials from various programs, such as meetings and conferences, tours, lectures, awards and dinners, films, and educational programs.

The records chronicle the ideology behind the Reconstructionist movement, the founding and activities of the Jewish Reconstructionist Foundation, and its growth and transformation from an ideology and movement into an established American Jewish denomination, Reconstructionist Judaism. The records also document two seminal figures in Reconstructionist Judaism, Mordecai Menahem Kaplan and Ira Eisenstein. Included in the collection are the administrative records of the Foundation (minutes, financial records, bylaws), publications produced by the Foundation including manuscript submissions for the influential publication The Reconstructionist, correspondence, sermons, prayer books produced by the Foundation, syllabi, sheet music, photographs, and speeches, among other material. In the correspondence are letters from Martin Buber, J. Edgar Hoover, and Albert Schweitzer.

The children and descendants of Isaac Mendes and Rachel Levy Seixas included individuals who had a great impact on communal affairs and colonial Jewish life in New York, Philadelphia, Newport, and Richmond. Though this collection does not preserve the total volume of papers produced by every family member, the documents contained herein demonstrate the importance of the family in both Jewish and secular life in late 17th and early 18th century North America.

The collection is valuable to researchers studying the Seixas family; civic, mercantile, and religious contributions of Jews in the colonial era; Jewish communities in New York, Philadelphia, Newport, and Richmond; the importance of religion to Colonial Jews; Jewish participation in the Revolutionary War, the War of 1812, and World War I; Jewish converts to Christianity; Jews as masons; and Congregation Shearith Israel of New York.

Prominent individuals in this collection include: Ephraim Hart, Grace Seixas Judah, Mrs. Jesse Judah, Israel Baer Kursheedt, Sarah Seixas Kursheedt, Hayman Levy, Nicholas Low, Isaac Moses, Naphtali Taylor Phillips, Benjamin Mendes Seixas, David G. Seixas, Gershom Mendes Seixas, Isaac Benjamin Seixas, Isaac M. Seixas, Jacob B. Seixas, Joshua Seixas, and Moses Mendes Seixas.

The collection includes: account records, books, circumcision instructions and register, correspondence, drawings, estate papers, a eulogy, family trees, legal documents, petitions, photographs, prayer books, a sermon, and shipping records.

This collection is arranged into four series: Series I: Family Papers; Series II: Moses Seixas (1744-1809); Series III: Gershom Mendes Seixas (1746-1816) and descendants; and Series IV: Benjamin Mendes Seixas (1748-1817) and descendants.